Guru
Joined: 07/08/2011
Location: AustraliaPosts: 6181
| Posted: 02:15am 02 Feb 2025 |
Including the start bit, you need 4 bits to set the configuration, one null bit and 10 data bits
By adding a low bit before the start bit, you have 16 bits nicely aligned
You can choose to use 8 bit spi or 16 bit spi. Either will work,
'
OPTION EXPLICIT
OPTION DEFAULT INTEGER
DIM data0, data1
SETPIN 27, DOUT ' pin 27 ADC chip enable active low
PIN(27) = 1 ' ADC chip disabled
SETPIN 11, 20, 19, SPI2 ' assign SPI I/O pins, RX, TX, CLK
PAUSE 20
'using 16 bit spi
SPI2 OPEN 100000, 0, 16 ' speed 1MHz, SPI mode 0, 16 bits data
DO
PIN(27) = 0 ' ADC chip enabled
data0 = SPI2(&b0110100000000000)' get data from ADC channel 0
data1 = SPI2(&b0111100000000000)' get data from ADC channel 1
PIN(27)=1 ' ADC chip disabled
PRINT data0,data1
PAUSE 5000
LOOP UNTIL INKEY$<>""
SPI2 CLOSE ' close the channel
'using 8 bit spi
SPI2 OPEN 100000, 0, 8 ' speed 1MHz, SPI mode 0, 8 bits data
DO
PIN(27) = 0 ' ADC chip enabled
data0 = SPI2(&b01101000)<<8 + SPI2(0)' get data from ADC channel 0
data0 = data0 AND &h3FF
data1 = SPI2(&b01111000)<<8 + SPI2(0)' get data from ADC channel 1
data1 = data1 AND &h3FF
PIN(27)=1 ' ADC chip disabled
PRINT data0,data1
PAUSE 5000
LOOP UNTIL INKEY$<>""
SPI2 CLOSE ' close the channel
OPTION EXPLICIT
OPTION DEFAULT INTEGER
DIM data0, data1
SETPIN 27, DOUT ' pin 27 ADC chip enable active low
PIN(27) = 1 ' ADC chip disabled
SETPIN 11, 20, 19, SPI2 ' assign SPI I/O pins, RX, TX, CLK
PAUSE 20
'using 16 bit spi
SPI2 OPEN 100000, 0, 16 ' speed 1MHz, SPI mode 0, 16 bits data
DO
PIN(27) = 0 ' ADC chip enabled
data0 = SPI2(&b0110100000000000)' get data from ADC channel 0
data1 = SPI2(&b0111100000000000)' get data from ADC channel 1
PIN(27)=1 ' ADC chip disabled
PRINT data0,data1
PAUSE 5000
LOOP UNTIL INKEY$<>""
SPI2 CLOSE ' close the channel
'using 8 bit spi
SPI2 OPEN 100000, 0, 8 ' speed 1MHz, SPI mode 0, 8 bits data
DO
PIN(27) = 0 ' ADC chip enabled
data0 = SPI2(&b01101000)<<8 + SPI2(0)' get data from ADC channel 0
data0 = data0 AND &h3FF
data1 = SPI2(&b01111000)<<8 + SPI2(0)' get data from ADC channel 1
data1 = data1 AND &h3FF
PIN(27)=1 ' ADC chip disabled
PRINT data0,data1
PAUSE 5000
LOOP UNTIL INKEY$<>""
SPI2 CLOSE ' close the channel
You may need to toggle the CS pin between the two readings.
I don't have the MCP3002 so untested.
Jim