Led Current Programming; Indicator Led Mode; Flash Led Programming; Software Or Hardware Strobe For Flash - Analog Devices ADP1650 User Manual

UG-139

LED CURRENT PROGRAMMING

Before changing settings in the ADP1650 registers, you must
enable the I 2 C interface by clicking the EN button in Section 8
of the user registers window (the button turns green and the EN
LED on the motherboard lights up). This sets the EN pin of the
ADP1650 high.

INDICATOR LED MODE

Using the indicator LED can be a quick way to verify
communication between the software and the ADP1650.
1. Set GPIO2 Config in Section 3 of the user registers
window to Indicator. Then update Register 0x02 by
pressing Refresh 0x02. The red indicator LED on the
motherboard should turn on.
2. Ensure that Header J12 on the demo board has Pin 2 and
Pin 3 shorted with a jumper to connect the GPIO2 pin to
the red LED on the motherboard.
3. To change the indicator LED current, use Section 3 of the
user registers window.
4. Ensure a write to the ADP1650 by clicking the appropriate
refresh button in Section 6 on the right side of the user
registers window. The refresh button turns red to indicate
that a setting has changed for a register and must be
updated.
5. Turn off the indicator LED by setting GPIO2 Config to
Hi-Z before performing the flash/assist light evaluation.

FLASH LED PROGRAMMING

1. To program the LED current, set Torch/Assist Current
and Flash Current in Section 2 of the user registers
window, and click the Refresh 0x03 button.
2. For USB-only powered demonstrations, use a maximum
Flash Current setting of 300 mA to avoid exceeding the
USB current source capability of 500 mA.

SOFTWARE OR HARDWARE STROBE FOR FLASH

There are three ways to initiate flash.
I 2 C Enabled Flash
1. Set EN in Section 8 of the user registers window.
2. In Section 1 of the window, set LED Mode to Flash, set
Output Enable to ON, and set Strobe Mode to S/W.
Refresh 0x04 should turn red to indicate that the front
panel settings must be written to the ADP1650.
3. Click the Refresh 0x04 button to initiate flash.
4. To program the length of the flash event, set the value
under S/W Flash Timer in Section 2 of the window and click
the Refresh 0x02 button.
Strobe Enabled Flash – Using the STROBE Button on the
Motherboard (Most Common)
1. Set EN in Section 8 of the user registers window.
2. In Section 1 of the window, set LED Mode to Flash, set
Strobe Mode to H/W, and set Output Enable to ON.
3. Click the Refresh 0x04 button.
4. In Section 8 at the top left of the window, set Strobe pin
Source to Push Button on Demo Board.
5. Press the STROBE button on the motherboard to initiate
flash.
Strobe Enabled Flash – Using the User Registers Window
1. Set EN in Section 8 of the user registers window.
2. In Section 1 of the window, set Output Mode to Flash, set
Strobe Mode to H/W, and set Output Enable to ON.
3. Click the Refresh 0x04 button.
4. In Section 8 of the window, set Strobe pin Source to
Micro-controller Driven.
5. Click the STROBE button in Section 8 of the window to
initiate flash.
6. Program the length of the flash event by setting the value
under S/W Flash Timer in Section 2 and clicking the
Refresh 0x02 button.
7. To initiate flash again, click Refresh 0x04 and click
STROBE again. STROBE can be enabled either from the
user registers window by clicking STROBE in Section 8 or
from the hardware by pressing the STROBE button on the
motherboard.

SOFTWARE OR HARDWARE TORCH

The torch can be activated in two ways: by pressing the TORCH
button on the motherboard or by completing the following
steps in the user registers window:
1. Set EN high (green) in Section 8 of the user registers
window.
2. In Section 1 of the window, set LED Mode to Assist.
3. Set Output Enable = 1 by clicking the Output Enable
button (green = 1).
4. Click the Refresh 0x04 button.

TIMEOUT DURATION PROGRAMMING

Timeout is hardware limited to a maximum of 1600 ms.
1. To set the desired flash timeouts, change the setting under
the Flash Timer box in Section 2, and click the Refresh
0x02 button. The timeout doubling bit is set by default by
the software.
2. To get 50 ms resolution, contact your Analog Devices field
applications engineer (FAE).
Rev. A | Page 6 of 16
Evaluation Board User Guide