mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
85 lines
3.2 KiB
Markdown
85 lines
3.2 KiB
Markdown
|
|
[](https://github.com/marketplace/actions/arduino_ci)
|
|
[](https://github.com/RobTillaart/MCP_ADC/blob/master/LICENSE)
|
|
[](https://github.com/RobTillaart/MCP_ADC/releases)
|
|
|
|
# MCP_ADC
|
|
|
|
Arduino library for MCP3002 MCP3004 MCP3008 MCP3202 MCP3204 MCP3208
|
|
|
|
|
|
## Description
|
|
|
|
This library reads the ADC ports of the MCP ADC convertors.
|
|
The chips are comunicates with SPI and support both hardware SPI or optional software SPI.
|
|
|
|
| type | bits | channels | notes |
|
|
|:----|:----:|:----:|:---|
|
|
| MCP3002 | 10 | 2 | |
|
|
| MCP3004 | 10 | 4 | |
|
|
| MCP3008 | 10 | 8 | |
|
|
| MCP3202 | 12 | 2 | |
|
|
| MCP3204 | 12 | 4 | |
|
|
| MCP3208 | 12 | 8 | |
|
|
|
|
Current version allows manual override of the hardware SPI clock as the speed is not
|
|
optimized per ADC type.
|
|
|
|
The MCP ADC allow single mode which compares voltage of a channel against GND.
|
|
Furthermore they allow a differential mode which compares two channels IN+ and IN-
|
|
to each other. if the IN+ is equal or below IN- the ADC will return 0.
|
|
|
|
Build into the library is a delta mode which is a software enhanced differential mode.
|
|
This delta mode can return negative values too.
|
|
|
|
|
|
## Interface
|
|
|
|
If the pins are not set in the constructor, the class will automatically
|
|
use the hardware SPI, otherwise it will use a software SPI
|
|
- **MCP3002(dataIn, dataOut, clock)** constructor 10 bit ADC 2 channel
|
|
- **MCP3004(dataIn, dataOut, clock)** constructor 10 bit ADC 4 channel
|
|
- **MCP3008(dataIn, dataOut, clock)** constructor 10 bit ADC 8 channel
|
|
- **MCP3202(dataIn, dataOut, clock)** constructor 12 bit ADC 2 channel
|
|
- **MCP3204(dataIn, dataOut, clock)** constructor 12 bit ADC 4 channel
|
|
- **MCP3208(dataIn, dataOut, clock)** constructor 12 bit ADC 8 channel
|
|
- **void begin(select)** set select pin.
|
|
- **uint8_t channels()** returns the number of channels
|
|
- **int16_t maxValue()** returns maxReading of adc, e.g. 1023.
|
|
This makes it easy to calculate relative measurements.
|
|
- **int16_t analogRead(channel)** reads the value of the channel
|
|
- **int16_t differentialRead(channel)** reads differential between two channels
|
|
Check datasheet for details
|
|
Note if the IN+ is equal or below IN- this function will return 0.
|
|
- **int16_t deltaRead(channel)** reads differential like above however it
|
|
will return a negative value if IN+ is below IN-.
|
|
- **void setSPIspeed(speed)** sets SPI clock in Hz, please read datasheet
|
|
of the ADC first to get optimal speed.
|
|
- **uint32_t getSPIspeed()** gets current speed in Hz
|
|
|
|
|
|
Differential channel table
|
|
|
|
| Channel | diff IN+ | diff IN- | MCP |
|
|
|:----:|:----:|:----:|----:|
|
|
| 0 | 0 | 1 | 3x02/3x04/3x08 |
|
|
| 1 | 1 | 0 | 3x02/3x04/3x08 |
|
|
| 2 | 2 | 3 | 3x04/3x08 |
|
|
| 3 | 3 | 2 | 3x04/3x08 |
|
|
| 4 | 4 | 5 | 3x08 |
|
|
| 5 | 5 | 4 | 3x08 |
|
|
| 6 | 6 | 7 | 3x08 |
|
|
| 7 | 7 | 6 | 3x08 |
|
|
|
|
|
|
## Future / ideas / improvements
|
|
|
|
- testing, a lot ...
|
|
- set SPI-speed in classes directly
|
|
- get / setF(float A, float B) => float readF(channel) output = A*value + B;
|
|
- analogRead (mask, int array ) read ports (set in mask) in an array in one call.
|
|
|
|
## Operations
|
|
|
|
See examples.
|