Guru
Joined: 11/02/2018
Location: AustraliaPosts: 1483
| Posted: 12:47pm 23 Sep 2022 |
As an experiment to see how fast a Pico can read a pin in a FOR - NEXT loop I wrote a program to read a DHT11 temp / humidity sensor and found you can fill an array at 15uS per sample.
CPUSPEED = 378000 kHz, a one digit pin number and all on one line. Every character slows it down.
Here is the relevant part.
'Data format - 80uS high start pulse, 50uS low + 25uS high = 0, 50uS low + 70uS high = 1
Dim integer n
' deliver 20 mS pulse to wake up DHT11
SetPin 1,dout,oc
Pin(1)=1
Pulse 1,20
Pause 19
SetPin 1,off
SetPin 1,din 'Get the samples
For n=0 To 329:a(n)=Pin(1):Next
SetPin 1, off 'Got the samples
'for max. speed the above 'for-next' must be on one line with fewest characters
Dim integer n
' deliver 20 mS pulse to wake up DHT11
SetPin 1,dout,oc
Pin(1)=1
Pulse 1,20
Pause 19
SetPin 1,off
SetPin 1,din 'Get the samples
For n=0 To 329:a(n)=Pin(1):Next
SetPin 1, off 'Got the samples
'for max. speed the above 'for-next' must be on one line with fewest characters
Edited 2022-09-24 09:01 by phil99