Hi, I'm building a digital temperature gauge. I purchased this kit from Jaycar a temperature switch with LCD readout **broken link removed**
There were no problems with assembling the kit as such, and it seems to work fine. The issue is that the supplied LCD is quite large and it is not backlit so it is not suitable for use in my car. I tried searching for alternative LED displays but they all seem to be overly large, or unsuitable for use with the kit.
So, I started looking at ADC's and LED segment drivers and found the MAX1496, an ADC with 3.5digit LED driver in one package.
The Jaycar kit uses a 0.1mV/degC signal to drive the original LCD. I changed some resistor values to increase amplification of the signal to 1mV/degC to better suit the MAX1496. The Jaycar kit also has a 5V power supply onboard which can drive the MAX1496.
I've assembled the MAX1496 on an experimental PC board, and it seems to work to an extent but it is having some issues.
I just wanted to clarify what is explained in the MAX1496 datasheet. If you go to page 9 on the datasheet it has pin descriptions.
How do I know if I want to use internal reference or external reference? Also, alot of the pin descriptions say bypass using a cap to ground. Does that mean the pin is connected to for example the analogue input and also to ground via a cap?
I have schematics of the Jaycar kit and of how I assembled the MAX1496 board. I can scan these in if you need them.
Thanks, Luke
There were no problems with assembling the kit as such, and it seems to work fine. The issue is that the supplied LCD is quite large and it is not backlit so it is not suitable for use in my car. I tried searching for alternative LED displays but they all seem to be overly large, or unsuitable for use with the kit.
So, I started looking at ADC's and LED segment drivers and found the MAX1496, an ADC with 3.5digit LED driver in one package.
The Jaycar kit uses a 0.1mV/degC signal to drive the original LCD. I changed some resistor values to increase amplification of the signal to 1mV/degC to better suit the MAX1496. The Jaycar kit also has a 5V power supply onboard which can drive the MAX1496.
I've assembled the MAX1496 on an experimental PC board, and it seems to work to an extent but it is having some issues.
I just wanted to clarify what is explained in the MAX1496 datasheet. If you go to page 9 on the datasheet it has pin descriptions.
How do I know if I want to use internal reference or external reference? Also, alot of the pin descriptions say bypass using a cap to ground. Does that mean the pin is connected to for example the analogue input and also to ground via a cap?
I have schematics of the Jaycar kit and of how I assembled the MAX1496 board. I can scan these in if you need them.
Thanks, Luke