Summary of Contents for Eggtimer Rocketry Proton
- Page 1 Eggtimer Proton User’s Guide Board RevA9 Software Rev. 1.01A © 2018 Eggtimer Rocketry All Rights Reserved - 1 -...
- Page 2 Eggtimer Proton Features WiFi-Enabled, SIX-Output logging flight computer with 120G Accelerometer Flexible deployment and arming modes, to handle virtually any flight scenario Any channel can perform any function… no dedicated "Drogue" or "Main" channels First three channels can be set for standard servos during deployments, variable servo travel...
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Page 3: Limited Warranty
If your Eggtimer Proton does not work properly after assembly, take a deep breath, get out the magnifying glass and a good light, and see if you have inadvertently created a solder bridge somewhere. - Page 4 .csv file, which can be imported into virtually any data analysis program. What makes the Proton different from most other flight computers is that it has a WiFi interface. Instead of using switches, jumpers, or a data cable to your laptop to program it, you simply connect to it with your phone, tablet, or computer using WiFi and a browser like Safari, Firefox, Internet Explorer, or Chrome.
- Page 5 Deployment Power (DP+/DP-) – Two solder pads for connecting a separate deployment battery. If you choose to use the Proton with a single battery for both the computer and the deployment side, you simply jumper the DP+ pad to the B+ pad, which provides the power for the deployment channels.
- Page 6 The Proton should be mounted so that the "UP" markings near the WiFi module face the nose of your rocket. You also want to make sure that the holes are drilled properly so that it faces as vertically as possible.
- Page 7 39mm-54mm rockets. We recommend using #22-#26 gauge wire for wiring to the Proton board, we like to use the #24 gauge stranded wire that’s found in Cat-5 network cables. It’s cheap, easy to find, and just the right size.
- Page 8 To wire up your Proton for dual-batteries, wire the +/positive side of the battery connector to the DP+ pad (next to the BATT pads), and the -/negative side of the battery to the DP- pad (located between the deployment output pads).
- Page 9 About Switches… The Proton is designed so that it will not self-arm itself. If you power it up, it will sit there on the Status page forever, changing the validation code every 60 seconds… you have to actually arm it using the validation code in order to start a flight.
- Page 10 For most installations, we recommend using a 2S 7.4V LiPo battery. You’ll need one that’s at least 300 mAH, since the Proton draws 85 mA (it’s WiFi… that’s the nature of the beast). You CAN get away with smaller batteries, IF (and ONLY IF) you connect the fully-charged battery up right before flying.
- Page 11 While we’re on the subject of 9V alkaline batteries, DO NOT, repeat, DO NOT use a 9V battery to power the Proton. At all. They don’t source much current, especially compared to a 2S LiPo. While it will appear to work fine once it’s new, it will quickly drain, and you will find that the range starts to rapidly decrease, and the Proton will appear to become unresponsive.
- Page 12 OK. If you battery only has a marginal current capability, the same short may cause the Proton to reset if the voltage drops below the processor threshold (about 2.8V). The deployment drivers are designed to shut down if the source voltage drops below 4V, so that theoretically shouldn't happen, but it's better not to chance it.
- Page 13 The Proton uses the WPA2-PSK WiFi connection protocol, so you need to enter an 8-digit passkey to connect. The passkey for your Proton is on a label on the WiFi module that you got when you built it. It’s also on a label on the package. If you accidentally lose it, you can also get it by connecting an Eggtimer USB-TTL data cable to the programming header.
- Page 14 The Status Page The first thing you will see is the Status Page. It tells you what your Proton is doing, and gives you some other important information: ◦...
- Page 15 Proton_2abcd 1.01a Status: Disarmed Validation Code: 4567 ………………………… Channel 1: Drogue Change Delay: 0.0 Settings Channel Status: ON Channel 2: Main Change Altitude: 500 Settings Channel Status: ON Channel 3: Airstart Delay: 2.2 Settings Channel Status: OFF Channel 4: OFF Change Channel Status: OFF Channel 5: Clustered Change Channel: 3...
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Page 16: Calibrating The Accelerometer
60 seconds. When it refreshes, you’ll hear a little beep from the speaker... this also lets you know that you’ve got power and are connected to your Proton. In addition, every time the page refreshes a new validation code is created. You can force a page refresh by hitting the refresh icon on your browser, or by clicking on the ARM button without entering a validation code or entering an invalid validation code. - Page 17 This means that if a channel is enabled there must be continuity; if a channel fails the continuity test then you will not be able to arm your Proton. You can tell very easily from the Status page if it’s ready to fly, because any failed channels with have the continuity status highlighted in RED.
- Page 18 In addition, your rocket must be in a vertical state, i.e. it must be pointing "UP" to arm it. If the Proton sees that the G's are under 0.80G or over 1.20G it will not arm. Note that the accelerometer will drift over time, so you need to perform a calibration before you fly it in order to compensate for this.
- Page 19 5 seconds, so don’t do it right before launching, and remember to close the browser when you’re done. See the section titled “Flying With Your Proton” for a further discussion of flight events. - 19 -...
- Page 20 The Deployment Flight Settings Pages Each of the six channels can be programmed to perform in any of several different modes. Some of them are "traditional" in the sense that if you've flown with other flight computers (particularly an Eggtimer Quantum) you'll be familiar with their function. The modes are: OFF - Just what it says…...
- Page 21 The purpose of this page is to set the delay from nose-over for firing the drogue, and other related settings. For most dual-deployment flights, you’ll probably want the drogue to fire as close to apogee as possible, in the Proton this would be approximately one second after apogee. - 21 -...
- Page 22 In general, if you’re using dual-deployment then you should set this to ZERO. The other settings are designed for delaying the drogue using the Proton as a backup deployment controller in a dual-controller redundant setup, or for special-purpose uses (i.e. the 5-second setting is designed for ejecting ARLISS CanSats...
- Page 23 500’ is the default setting when you first power up your Proton, it’s adequate for probably 80% of all flights. If you field is smaller or if there's a fair amount of wind, you’re going to want to take that down a bit, so your rocket doesn’t drift as far when the Main is deployed.
- Page 24 Proton_2abcd 1.01a Main Settings Channel 2: Altitude: 500 Deploy Mode: Igniter v Pulse Width: 2 secs Failsafe: Time 1.0 Vel. 100 Submit Altitude (100'-2000', default is 500') : Deployment altitude for the event. When your rocket descends from nose-over to this altitude or below, the channel will fire.
- Page 25 to drift a lot more than a normal drogue-main deployment would, but that's better than having your rocket impact the ground at high speed, and/or having the main chute shred because the deployment velocity is several hundred feet per second, and still having a high speed ground hit. The proper values of the Failsafe parameters will depend on the size of your drogue chute (or lack thereof if you're going drogueless), the size of your Main chute (if it's large you may want to deploy it a little slower to avoid damaging it), the size/weight of your rocket (smaller lighter...
- Page 26 Launch Detect Altitude (LDA) (100’-500’ by 50’, default 200’) This setting allows you to select at what altitude the Proton decides that a valid flight has started. The 200’ default is good for most flights. However, there may be some cases in which you may want to turn it up, and some very special cases in which you may want to turn it down.
- Page 27 It is assumed that whichever one of these came later is an accurate start of flight. About Sampling Rates and Memory Usage At this point you may be wondering about how long a flight the Proton can record before running out of memory, and what happens if that occurs. The Proton saves about 2,000 samples for each flight.
- Page 28 If you have an extreme flight, say 50,000’, it may take a bit longer to get up there, let’s say 45 seconds. That’s 900 samples, leaving 1100. If you take the rate down to 1 sample per second (reasonable since the events are happening relatively slowly and the air is pretty thin at 50K), you still have 1100 seconds, or over 18 minutes.
- Page 29 At the Pad Put the rocket up on the rail/rod, raise it, then go to the Proton’s status page. You should see that the Accel value is close to 1.00, and it should be AQUA, indicating that it thinks it's pointed "up". If it is RED, lower the rocket to a horizontal position, go into the Settings menu, select the Calibrate link, and select Auto Adjust.
- Page 30 After a few seconds, you’ll hear a few beeps, then after about 10 seconds of silence (as it takes baseline measurements) you’ll hear the “I’m ready” beeping, approximately once per second. Connect your igniter, test the continuity, then go back to the safety zone to await your flight. If you’re new to dual-deployments, you can see that it’s a lot more involved than just stuffing some wadding and the parachute into the tube, popping in the motor, and hooking up the igniter.
- Page 31 The Proton detects that your rocket is on the ground when the barometrically-detected AGL altitude varies by less than 30 feet for over 5 seconds. Once on the ground, the Proton will start beeping out the maximum altitude continuously for anyone within earshot to hear. The beeps work like this:...
- Page 32 Summary page for the flight that you just completed. Note that it may take 10-15 seconds to bring up the Flight Summary page after you connect to the Proton, because it sends out the page after it’s done beeping out the altitude, so you have to wait until it goes quiet for a few seconds. Once you the connection, you'll get the Flight Summary page that you see below.
- Page 33 The Proton saves your last 14 flights: settings, summary data, and detail data. Clicking on the ‘Flights’ link in the Proton’s Status page takes you to an index page that allows you to select the flight that you want to review. Note that each flight has an index number from 1-14, this is the memory location that it’s in, and each flight has a Flight number that is sequential from 1 to however...
- Page 34 You get there by clicking the Flights link from the Status Page. After you land, you can also connect to it… the Proton will show you only the status for the current flight, plus the detail, until you power-cycle it. Here, we'll click on Flight #2, the one with 1827 as the apogee...
- Page 35 ASL Alt – The Above-Sea-Level reading of your launch site. Temp – The temperature in Farhenheit at the time of launch. This will be very accurate if the Proton has been powered on for 10-15 minutes, but will tend to be on the low side if you fly shortly after powering up.
- Page 36 As you can see, that’s a lot of stuff to look at. Particularly right after landing, it gives you a pretty good idea of what happened. For example, we did a test in which we intentionally didn’t install a drogue charge and left out the motor eject, and turned on FailSafe as a test. (We don’t recommend that YOU do this, though…) We expected the Main to pop 3-4 seconds after apogee, but that didn’t happen, instead it came out at about 500’...
- Page 37 We’ve had good luck with WPS Office for Android and iOS, it’s free and works very well with the simple .csv data that the Proton sends out, and it’s very easy to get a flight/event graph. For a Windows laptop, we use Excel, but any data analysis program that can take a .csv file will work.
- Page 38 VelocAcc (velocity) - the velocity derived from the accelerometer in ft/sec AltAcc (altitude) - the DISTANCE TRAVELED derived from the accelerometer in ft. Then you will see the FILTERED values... FAlt (filtered altitude) – the FILTERED pressure-derived altitude value FVeloc (filtered velocity) – the FILTERED barometric velocity for that sample, derived from the difference in FILTERED altitude between this ample and the previous sample and the time interval between them FAccelG (filtered acceleration) - FILTERED acceleration value from the accelerometer, in G's...
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Page 39: Appendix A - Deployment Channel Testing
(such as the Proton resetting in flight, or the igniter not firing because the battery can’t source enough current). - Page 40 If you do, you may blow out the output drivers or the FET. We’ve designed the Proton very conservatively, and the drivers provide current limiting to help protect the themselves and your battery. Nevertheless, it is still possible to blow something up if you try hard enough.
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Page 41: Appendix B: Using The Proton For Airstarts
Start of Flight, of SOF. Each output channel on the Proton is an independent timer, triggered by the SOF. They can be used for igniting a motor, firing a charge to separate stages, or just about anything else you can think of. - Page 42 Note: This Appendix is not meant to be an exhaustive description of all of the Proton’s features and its operation, it’s a supplement to the Eggtimer Proton User’s Manual, specifically addressing the airstart functions.
- Page 43 (see the Appendix). Setting Up Two-Stage Airstarts with Your Proton Before you do anything, you MUST use some kind of simulation program to map out the flight, so that you have a very good idea of what altitude and velocity your rocket will be attaining at three critical points: burnout, separation, and sustainer motor ignition.
- Page 44 Burnout This is when your motor’s thrust stops. Every motor has published thrust curves that give you that exact information, you can get them either from the manufacturer’s web site, a third-party web site like thrustcurve.org, or from the data sheet that’s typically include with the motor. Note that these figures are averages based on tests of a number of samples;...
- Page 45 You just mount your Proton in the interstage (with a suitable bulkhead, of course!), and you can use the drogue channel for the booster’s chute deployment at nose-over if you wish.
- Page 46 This makes it somewhat easier to do parachute redundancy for the booster, you can use a single Proton in the booster for the separation charge and chute at nose-over, and use the booster’s motor ejection as the backup for the chute. If the booster drag separates (intentionally or otherwise), your sustainer is still going to light because the igniter isn’t tied to the interstage.
- Page 47 In general, we recommend that your booster motor should have at least a 10:1 thrust:weight ratio at launch. Assuming that your rocket is stable (and a typical long and skinny two-stage rocket tends to be a bit overstable), it’s going to go straight up, and it will be be pointing up when the sustainer fires. Long-burn motors in the booster won’t get the air flowing over the fins and any disturbance (wind, slightly misaligned fins) can make your rocket point off-axis and possibly lead to you chasing your sustainer for a very long distance.
- Page 48 Avoid colored motors (red/green/pink), they generally take awhile to light and/or come up to pressure. The setup for the Proton is the same as you would use for lighting the sustainer of a two-stage rocket, except you don’t have a separation charge. That leaves another channel free for something else, possibly redundant igniters or a charge that releases the pods after burnout (you’d use motor...
- Page 49 Using the Altitude and Velocity Qualifications One thing that the Proton can do that most airstart timers can not is to qualify an ignition using barometric altitude or velocity. This allows you to pretty much insure that your rocket is pointing “up”, because those qualifications can only happen if your rocket doesn’t have a significant...
- Page 50 When you get near Mach 1, the pressure buildup drops the perceived altitude (and also the perceived velocity) so the Proton “thinks” that it’s going lower and slower than it actually is. You’re more likely to have a failure to trigger due to a failed qualification with high- thrust motors, one more reason to avoid them.
- Page 51 Hobby rocketry flights are meant to be flown near-vertical, with maybe a small angle away from the flight line for safety. Theoretically, your rocket is pointed up and keeps going up. If you're doing an airstart, you want the motor to fire as close to vertical as possible, to prevent the rocket from going horizontally under power.
- Page 52 When the breakwire is being used, the Proton will not arm if it sees that it’s OPEN, and the channel won’t fire if it sees that it’s still CLOSED. The classic breakwire is attached to the pad somehow, and is used with the sustainer motor to prevent it from firing until the rocket has left the pad, but there are lots of other things you could do.
- Page 53 Eggtimer Proton Airstart Quick Reference General Rules for Successful Airstarts SIMULATE EVERYTHING FIRST!!! Your booster motor’s thrust:weight ratio should ideally be 10:1 or above. Your separation time should be at least 120% of the motor’s burn time.
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Page 54: Appendix C - Using Servos With The Proton
Ground lead of the servo (which should be connected to your servo battery's "-" lead) should be connected to a ground point on the Proton; the "G" pad of the Servo pads is ideal for this. We recommend that you connect a resistor in series with the Servo-Signal lead to help prevent noise…... - Page 55 R/C servos then you’ll want to hear. At this point, bring up your Proton, go to Settings and set the channel you’re using for servo deployment, then go back into the Settings page and select the direction and skew. You should now be able to go into the Deployment Test page and move the servo.
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Page 56: Appendix D - Browser Compatibility
Appendix D - Browser Compatibility Here are some notes regarding browser compatibility. They may or may not apply to your platform… there are a LOT of different hardware/software combinations, particularly with Android. In general, the manufacturer’s browser is usually the best choice, except with Android in which case we recommend Firefox. -
Page 57: Appendix E - Recovering The Passkey
The passkey is an eight-digit number generated by a random number algorithm the first time that your Proton is powered on, and is saved in EEPROM memory at that time. It’s going to be unique for every Proton. There should be a label on the little baggie that the WiFi module came in with the passkey (you kept it, right?), but it’s easy to get it if you lose it…... - Page 58 Eggtimer Proton Quick Start Guide Power: 7.4v/2S LiPo, 300 mAH or higher recommended. Bigger is Better… Connect to the two BATT terminals, RED generally goes to "+" and BLACK to "-" Deployment Power: Any battery that will operate your deployment device is OK..
- Page 59 Drogue Settings Click on Change link next to Drogue settings to change 0.1-9.0 secs by 0.1 secs, 3.0 – 9.0 secs by 1.0 secs Drogue mode (igniter/servo) Drogue on-time or servo direction/skew Main Settings Click on Change link next to Main settings to change OFF, Nose-Over, 100’-500’...
- Page 60 Deployment Channel Testing Check your Settings first, set appropriately Go to the test page… 192.168.4.1/test Select the channel to fire… it uses the settings from the Global Settings page Enter the 4-digit validation code then click TEST To abort a test, close the page before it counts down to zero - 60 -...