Hello,
I am using DAC0832 (National Instruments) to convert from digital to analog in order to fade in and out two LEDs in parallel.
All the active low inputs XFER, WR2, CS, are connected to ground, and ILE is connected to +5V logic input. Vcc and Vref are also +5V input from the microcontroller (HCS12DT).
The data is sent through port A of the microcontroller.
Iout1 is inputted to the non-inverting input of LM324, and the inverting input is set to GND. R feedback is connected to the output of LM324 and the output is supposedly to be connected to the LEDs. Vcc+ of the LM324 is 7V and Vcc- is GND.
Iout2 is grounded. AGND and GND are GND.
If the +5V power was off, and the microcontroller wasn't even connected, I would get 5.9V out of the output of LM324. When it is connected and power is on, guess what I get? 5.9V. If I latch digital input of zero I get 5.9V, if I latch 0xFF, I get 5.9 V. (Values may slightly change +-0.02V).
I'm pretty sure that the op-amp is working because I tried it over other devices and I got a range of readings from 0 up to something around 6 Volts.
What is going on?
I am using DAC0832 (National Instruments) to convert from digital to analog in order to fade in and out two LEDs in parallel.
All the active low inputs XFER, WR2, CS, are connected to ground, and ILE is connected to +5V logic input. Vcc and Vref are also +5V input from the microcontroller (HCS12DT).
The data is sent through port A of the microcontroller.
Iout1 is inputted to the non-inverting input of LM324, and the inverting input is set to GND. R feedback is connected to the output of LM324 and the output is supposedly to be connected to the LEDs. Vcc+ of the LM324 is 7V and Vcc- is GND.
Iout2 is grounded. AGND and GND are GND.
If the +5V power was off, and the microcontroller wasn't even connected, I would get 5.9V out of the output of LM324. When it is connected and power is on, guess what I get? 5.9V. If I latch digital input of zero I get 5.9V, if I latch 0xFF, I get 5.9 V. (Values may slightly change +-0.02V).
I'm pretty sure that the op-amp is working because I tried it over other devices and I got a range of readings from 0 up to something around 6 Volts.
What is going on?