dave
Joined: 21 Dec 2003
Posts: 7
Location: Sheffield, South Yorks, UK
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| MCP6S28/1/2/5/8 PGA code |
 Posted: Tue Dec 07, 2004 6:13 pm |
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MPLAB V7
PCH 3.213
Runs fine in sim not hardware tested it yet but will amend this thread when I have, hopefully by the end of the week.
| Code: |
//Driver file for Microchip 6s281/2/6/8 channel PGA amplifiers
//Devices can operate in mode 0,0 and mode 1,1 this driver file is for mode 0,0
//Date 9-12-04
//Refer to the data sheet for more information and Microchips AN248 application note
//Instruction register must be accessed first to select either the Gain register or the channel select register
//data is sent as a 16 bit word
// Definitions
//Gain
#define gain1 0b0100000000000000 // Gain of 1
#define gain2 0b0100000000000001 // Gain of 2
#define gain4 0b0100000000000010 // Gain of 4
#define gain5 0b0100000000000011 // Gain of 5
#define gain8 0b0100000000000100 // Gain of 8
#define gain10 0b0100000000000101 // Gain of 10
#define gain16 0b0100000000000110 // Gain of 16
#define gain32 0b0100000000000111 // Gain of 32
//Channels
#define channel0 0b0100000100000000 // channel 0
//#define channel1 0b0100000100000001 // channel 1
//#define channel2 0b0100000100000010 // channel 2
//#define channel3 0b0100000100000011 // channel 3
//#define channel4 0b0100000100000100 // channel 4
//#define channel5 0b0100000100000101 // channel 5
//#define channel6 0b0100000100000110 // channel 6
//#define channel7 0b0100000100000111 // channel 7 //don't need these if using only the 6s281 single channel
//Data format is as follows the first byte in the word (0b01000000<--register select bit) this is automatically
//sent to the pga instruction register
//0b01000000 =gain register select / 0b01000001 =channel register select",
//
//the second half of the word is then automatically re-directed to either the channel select
//or gain select register
//===================================================
// definitions for "instructions"
//#define PrgGain 0b01000000 // instruction for gain register
//#define PrgChannel 0b01000001 // instruction for channel register
//#define PrgShdn 0b00100000 // instruction to shutdown PGA
//Select your own pins for the interface
#define PGA_CS PIN_A0
#define PGA_SCLK PIN_A1
#define PGA_DO PIN_A2
//===================================================
//These PGA's require a 16 bit word as stated above
void gain_set(int16 gain_data)
{
int8 data_count;
output_bit(PGA_SCLK,0); //make sure clock is idling low set this up in intialisation routine as well
output_bit(PGA_CS,0); // select PGA set high in initialisation routine!
delay_us(1);
for(data_count=0;data_count<16;data_count++)
{
output_bit(PGA_DO,shift_left(&gain_data,2,0));
output_bit(PGA_SCLK,1); //clk in the data
delay_us(1);
output_bit(PGA_SCLK,0);
}
output_bit(PGA_SCLK,0); //make sure clock is idling low
output_bit(PGA_CS,1); // deselect PGA at this ponit this will implement the changes
// in either channel selection or gain selection
}
//copy of above for channel selection
void chan_set(int16 chan_data)
{
int8 data_count;
output_bit(PGA_SCLK,0); //make sure clock is idling low set this up in intialisation routine as well
output_bit(PGA_CS,0); // select PGA
delay_us(1);
for(data_count=0;data_count<16;data_count++)
{
output_bit(PGA_DO,shift_left(&chan_data,2,0));
output_bit(PGA_SCLK,1); //clk in the data
delay_us(1);
output_bit(PGA_SCLK,0);
}
output_bit(PGA_SCLK,0); //make sure clock is idling low
output_bit(PGA_CS,1); // deselect PGA at this ponit this will implement the changes
// in either channel selection or gain selection
}
|
Dave |
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