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| author | Ayke van Laethem <[email protected]> | 2023-05-09 16:46:50 +0200 |
|---|---|---|
| committer | Ron Evans <[email protected]> | 2023-05-09 19:51:05 +0200 |
| commit | f4c8c37b7b4a618574f8255b7b089b34f44a247e (patch) | |
| tree | fc34dbe4159e80a262eb02bc36cc6a205bc93433 | |
| parent | 868812717f432349f911bc45b4f7945d942388fa (diff) | |
| download | tinygo-f4c8c37b7b4a618574f8255b7b089b34f44a247e.tar.gz tinygo-f4c8c37b7b4a618574f8255b7b089b34f44a247e.zip | |
nrf: add ADC oversampling support
This is a lot easier to support than on other chips, and results in
noticeably better output when set to a higher value.
| -rw-r--r-- | src/machine/machine_nrf52xxx.go | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/src/machine/machine_nrf52xxx.go b/src/machine/machine_nrf52xxx.go index 2989e14dd..c4605d582 100644 --- a/src/machine/machine_nrf52xxx.go +++ b/src/machine/machine_nrf52xxx.go @@ -24,7 +24,8 @@ func (a ADC) Configure(config ADCConfig) { // enabled. nrf.SAADC.ENABLE.Set(nrf.SAADC_ENABLE_ENABLE_Enabled << nrf.SAADC_ENABLE_ENABLE_Pos) - // Configure ADC. + // Use fixed resolution of 12 bits. + // TODO: is it useful for users to change this? nrf.SAADC.RESOLUTION.Set(nrf.SAADC_RESOLUTION_VAL_12bit) var configVal uint32 = nrf.SAADC_CH_CONFIG_RESP_Bypass<<nrf.SAADC_CH_CONFIG_RESP_Pos | @@ -69,6 +70,34 @@ func (a ADC) Configure(config ADCConfig) { configVal |= nrf.SAADC_CH_CONFIG_TACQ_40us << nrf.SAADC_CH_CONFIG_TACQ_Pos } + // Oversampling configuration. + burst := true + switch config.Samples { + default: // no oversampling + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Bypass) + burst = false + case 2: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over2x) + case 4: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over4x) + case 8: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over8x) + case 16: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over16x) + case 32: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over32x) + case 64: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over64x) + case 128: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over128x) + case 256: + nrf.SAADC.OVERSAMPLE.Set(nrf.SAADC_OVERSAMPLE_OVERSAMPLE_Over256x) + } + if burst { + // BURST=1 is needed when oversampling + configVal |= nrf.SAADC_CH_CONFIG_BURST + } + // Configure channel 0, which is the only channel we use. nrf.SAADC.CH[0].CONFIG.Set(configVal) } |