Hi everyone. I have bought the LP55231 board and I have started testing it. I attached different LEDs to the D1-D9 output channels. My first question is: Have I to dismiss the 3 LEDs attached on the board?. The LEDs I have attached are all red (the ones of the arduino kit), but i have also a white led for testing. I have noticed that if setting the maximum PWM duty cycle and the maximum current (I am using the LP55231 library) the output voltage is 2V for all of the channels where I have connected the red leds. If I take the white LED and I connect it to (for example to D1) the output voltage increases up to 3.03V around. If it is like the channel recognizes the attached led. While if i connect the same white led to the channel D7-8-9 the maximum voltage is around 2V. So my question is: from the previous mentioned channels D7-D8-D9 is the maximum voltage output around 2V (because they are responsible for red leds)? And how does the pcb recognizes the LED (I have the same settings for driving current (255) and pwm(255), so I expected the maximum output voltage. I am powering the board with 5dvc of my teensy. Thanks for the reply.
To drive external LEDs, you need to disable the on-board LEDs by cutting JP4-JP6.
The voltage drop across an LED is dependent on the material the LED is made of and the color, so a red LED, when on, will drop around 1.7 - 2.2V. You should set the current based on the operating current of the LED (indicator LEDs need, and can handle, less current than ones used for illumination) and then use PWM to adjust the brightness.
/mike
/mike
Just another question. If I need to control 9 WHITE leds with the driver, is there a possible way to increase the voltage of the red channels D7-D8-D9 like the other channels? In this way I can avoid the use of another driver in deasy-chain configuration
Sorry please anwer me as soon as possible. I tried to solder D1-D2-D3 but i have not obtained any results and on board leds are still on. Is the contact isolated? What have I to do to disable these leds?
https://learn.sparkfun.com/tutorials/lp … okup-guide describes how to cut the jumpers to disable the on-board LEDs. To drive white LEDs on D7-D9, you need to power the board from 5V (that will allow all the outputs to run white LEDs). If you do this, you need to either use a processor that has 5V outputs or use a level shifter on the interface lines.
/mike
I am working with LP55231 led-driver. Driver ic has 3 engines. but the engine is not triggered with CC1312/CC1352 MCU
I can operate LP55231 without an Engine with CC1312/52. (using PWM)
I tested the same hardware with ESP32 and Arduino mega. with these MCUs, it’s working fine but not working with cc1312/52
I have this led driver board
And this library which I have tested with ESP32 and Arduino mega.
(github.com/.../SparkFun_LP55231_Arduino_Library).
Can you help with this issue?
If you want the source file I can share in a private message.
For MCU to give low load consumption, I need to require all Engines to working mode
SDK version:- 6.10.00.29
RTOS :- Ti-Rtos7
Thanks in advance.