- Mon Jul 11, 2011 7:02 pm
#130005
This is in regards to the:
Graphic LCD Serial Backpack
sku: LCD-09352
I just hooked mine up and two things came to mind.
There is a limitation on the power supply voltage to avoid overloading the voltage regulator. But 6-7 volts is kind of an awkward range. If the LED backlight was supplied directly from the external power then regulated using PWM (which is already used to control brightness). You don't even need to monitor the average LED voltage, just monitor the incoming supply voltage and adjust the PWM accordingly.
The second idea was to add I2C support. It could be done by just connecting SDA and SCL to the existing TXD and RXD lines on the connector. It would require a way to configure it, either another solder jumper, a software approach or a different firmware version.
Using I2C would be a boon for AVR and other processors with only one serial port
Graphic LCD Serial Backpack
sku: LCD-09352
I just hooked mine up and two things came to mind.
There is a limitation on the power supply voltage to avoid overloading the voltage regulator. But 6-7 volts is kind of an awkward range. If the LED backlight was supplied directly from the external power then regulated using PWM (which is already used to control brightness). You don't even need to monitor the average LED voltage, just monitor the incoming supply voltage and adjust the PWM accordingly.
The second idea was to add I2C support. It could be done by just connecting SDA and SCL to the existing TXD and RXD lines on the connector. It would require a way to configure it, either another solder jumper, a software approach or a different firmware version.
Using I2C would be a boon for AVR and other processors with only one serial port