John Kemp / mcp3208

A library to interface to the MCP3208 SPI-based ADC from Microchip. This chip provides eight analogue inputs, providing converted 12-bit values via SPI.

Dependents:   Nucleo_MCP3208_Test Nucleo_MCP3208_Ticker_Test BBMv2_eps ref_BBMv2_eps ... more

mcp3208.h@1:316f86115221, 2011-05-24 (annotated)

Committer:
Kemp
Date:
Tue May 24 13:58:00 2011 +0000
Revision:
1:316f86115221
Parent:
0:d37e8cb188c1
Child:
2:93009a423b45
Now allows reading from differential inputs. Started documenting, fixed some silly bugs.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Kemp 0:d37e8cb188c1 1 #include "mbed.h"
Kemp 0:d37e8cb188c1 2
Kemp 0:d37e8cb188c1 3
Kemp 0:d37e8cb188c1 4 #ifndef MCP3208_H
Kemp 0:d37e8cb188c1 5 #define MCP3208_H
Kemp 0:d37e8cb188c1 6
Kemp 0:d37e8cb188c1 7
Kemp 1:316f86115221 8 enum Polarity {
Kemp 1:316f86115221 9 POL_EVEN_POSITIVE,
Kemp 1:316f86115221 10 POL_EVEN_NEGATIVE
Kemp 1:316f86115221 11 };
Kemp 1:316f86115221 12
Kemp 1:316f86115221 13
Kemp 1:316f86115221 14 /** Class for interfacing to the MCP3208 SPI-based ADC.
Kemp 1:316f86115221 15 *
Kemp 1:316f86115221 16 * This class will also allow interfacing to the MCP3204, but only four
Kemp 1:316f86115221 17 * inputs are provided by that chip, as opposed to the eight of the MCP3208.
Kemp 1:316f86115221 18 */
Kemp 0:d37e8cb188c1 19 class MCP3208
Kemp 0:d37e8cb188c1 20 {
Kemp 0:d37e8cb188c1 21 public:
Kemp 0:d37e8cb188c1 22 MCP3208(SPI bus, PinName cs);
Kemp 0:d37e8cb188c1 23 ~MCP3208();
Kemp 0:d37e8cb188c1 24
Kemp 1:316f86115221 25 /** Read from a single-ended input.
Kemp 1:316f86115221 26 *
Kemp 1:316f86115221 27 * @param channel The channel number to read from.
Kemp 1:316f86115221 28 *
Kemp 1:316f86115221 29 * @param returns The sampled value as a float between 0.0 and 1.0.
Kemp 1:316f86115221 30 */
Kemp 1:316f86115221 31 float read_input(int channel);
Kemp 1:316f86115221 32
Kemp 1:316f86115221 33 /** Read from a pair of differential inputs.
Kemp 1:316f86115221 34 *
Kemp 1:316f86115221 35 * In differential mode, the channels are referred to as 0 to 3, with
Kemp 1:316f86115221 36 * polarity set in a separate parameter. This avoids the user having to set
Kemp 1:316f86115221 37 * the polarity as part of the channel number or having channel numbers
Kemp 1:316f86115221 38 * increase by two (i.e. the channels being 0, 2, 4, and 6).
Kemp 1:316f86115221 39 *
Kemp 1:316f86115221 40 * @param channel The channel number to read from.
Kemp 1:316f86115221 41 * @param polarity The polarity of the differential signal.
Kemp 1:316f86115221 42 *
Kemp 1:316f86115221 43 * @param returns The sampled value as a float between 0.0 and 1.0.
Kemp 1:316f86115221 44 */
Kemp 1:316f86115221 45 float read_diff_input(int channel, Polarity polarity);
Kemp 0:d37e8cb188c1 46
Kemp 0:d37e8cb188c1 47 private:
Kemp 0:d37e8cb188c1 48 DigitalOut m_cs;
Kemp 0:d37e8cb188c1 49 SPI m_bus;
Kemp 0:d37e8cb188c1 50
Kemp 0:d37e8cb188c1 51 void select();
Kemp 0:d37e8cb188c1 52 void deselect();
Kemp 0:d37e8cb188c1 53 };
Kemp 0:d37e8cb188c1 54
Kemp 0:d37e8cb188c1 55
Kemp 0:d37e8cb188c1 56 #endif