The Analog-to-Digital Converter (ADC) can convert an analog input signal to a 10-bit binary digital representation of that signal. The ADC can also generate an interrupt upon completion of a conversion. This interrupt can be used to wake-up the device from SLEEP.
How does ADC interrupt work?
In electronics, an analog-to-digital converter (ADC, A/D, or A-to-D) is a system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal.
How do I enable ADC interrupt?
Programming steps:
- Set the value in ADMUX register according to the ADC channel and the reference voltage.
- Set the Prescaler bits accordingly in ADCSRA register.
- Set the ADEN bit to enable the ADC.
- Set ADIE bit to enable ADC interrupt.
- Set ADATE bit to enable auto triggering.
- Set ADSC bit to start conversion.
What are the 7 steps to be followed when setting up the PIC16F877A ADC?
In summary, here are the steps to be followed when setting up the PIC16F877A ADC:
- Configure the A/D module:
- Configure A/D interrupt (if desired):
- Wait the required acquisition time.
- Start conversion:
- Wait for A/D conversion to complete by either:
- Read A/D Result register pair (ADRESH:ADRESL), clear bit ADIF if required.
How do you set up ADC?
To get the ADC to work, we need to do the following tasks:
- Configure I/O pins as analog input(s) and configure ADC reference.
- Configure ADC registers to choose an analog pin.
- Configure ADC registers to enable the ADC.
- Configure ADC registers to set the acquisition time.
What is the resolution of DAC0808?
IC DAC0808 Parameters
| Parameters | IC DAC0808 |
|---|---|
| Settling time | 0.15 µs |
| Operating temperature range (C) | 0 to 70 |
| Rating | Catalog |
| Resolution | 8 Bits |
How do ADC channels work?
The ADC converts an analog input voltage to a 10-bit digital value. The ADC is connected to an 8-channel Analog Multiplexer which allows each pin of PortA to be used as input for the ADC. This allows the selection of any of the 8 channels, AGND, or a fixed voltage reference. The ADC has two different operating modes.
How many ADC channels are available in PIC16F877A?
It is a 10 bit ADC module. ADC module of the PIC16F877A controller has a 10-bit resolution output. That means an analog input converted into a corresponding 10-bit digital output and 7 channel ADC.
How do you program ADC in PIC16F877A?
PIC16F877A has an inbuilt 10 bit Successive Approximation ADC which is multiplexed among 8 input pins. The below table shows the ADC input pins multiplexed with other GPIO pins….PIC16F877A ADC pins.
| Adc Channel | Pic16f877a Pin | Pin Function |
|---|---|---|
| 0 | RA0 | AN0 |
| 1 | RA1 | AN1 |
| 2 | RA2 | AN2/VREF- |
| 3 | RA3 | AN3/VREF+ |
What are ADC channels?
Channels in an ADC is the number of analog values that can be read at the same time. Its like pins of a port. In a 8 channel ADC you will have 8 Analog input pins.
How many channels are in ADC?
8-channel
The ADC is connected to an 8-channel Analog Multiplexer which allows each pin of PortA to be used as input for the ADC. The analog input channel is selected by writing to the MUX bits in ADMUX. This allows the selection of any of the 8 channels, AGND, or a fixed voltage reference.
What is ADC interrupt enable in ADC?
ADIE: ADC Interrupt Enable – When this bit is set 1 and global interrupt enable bit I in SREG register is set then ADC conversion triggers interrupt. Bits ADPS2, ADPS1 and ADPS0 are the prescaler selection bits to divide the clock frequency at which ADC operates.
How to trigger the ADC while the CPU is running?
The second method is by using interrupts, so we can trigger the ADC in order to start a conversion and the CPU continues executing the main code routine. Upon conversion completion, the ADC fires an interrupt and the CPU is notified so that it can switch the context to the ISR handler and save the ADC conversion results.
What is the execution of the interrupt service routine?
The execution of the interrupt service routine is called a background thread. This thread is created by the hardware interrupt request and is killed when the interrupt service routine returns from interrupt (e.g., by executing a BX LR ). A new thread is created for each interrupt request.
How do you program a cyclic executive with interrupts?
Try to use the main loop to do all you need, trying to programm a cyclic executive and use the interrupts only to activate flags or read ADC values. You can achive this by setting times for each task, for example, read the ADC every 5ms, Set the LEDs every 10ms, etc.
