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| author | Peter Marheine <pmarheine@chromium.org> | 2019-11-26 10:52:17 +1100 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2019-11-26 07:17:58 +0000 |
| commit | b06d417e821c8681261d6e5f1139e5d101d147fc (patch) | |
| tree | ec802c532b53817b76088f4b4b183ee8e808b610 | |
| parent | ff9d3afc95c9b69b5ad91cf9ad17d4ac2812d1ca (diff) | |
| download | chrome-ec-b06d417e821c8681261d6e5f1139e5d101d147fc.tar.gz | |
puff: update PP3300_SNS divider
The schematic has changed to 9.31k / 47k resistors on this input.
BUG=b:1829597655
TEST=still builds
BRANCH=None
Change-Id: I2856df05b2611edd30d497a35bb871b8f5b173e9
Signed-off-by: Peter Marheine <pmarheine@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1935467
Reviewed-by: Andrew McRae <amcrae@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
| -rw-r--r-- | board/puff/board.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/board/puff/board.c b/board/puff/board.c index 77d632b9a3..7e27178469 100644 --- a/board/puff/board.c +++ b/board/puff/board.c @@ -98,11 +98,17 @@ const struct i2c_port_t i2c_ports[] = { const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports); const struct adc_t adc_channels[] = { - [ADC_SNS_PP3300] = { /* 9/11 voltage divider */ + [ADC_SNS_PP3300] = { + /* + * 4700/5631 voltage divider: can take the value out of range + * for 32-bit signed integers, so truncate to 470/563 yielding + * <0.1% error and a maximum intermediate value of 1623457792, + * which comfortably fits in int32. + */ .name = "SNS_PP3300", .input_ch = NPCX_ADC_CH2, - .factor_mul = ADC_MAX_VOLT * 11, - .factor_div = (ADC_READ_MAX + 1) * 9, + .factor_mul = ADC_MAX_VOLT * 563, + .factor_div = (ADC_READ_MAX + 1) * 470, }, [ADC_SNS_PP1050] = { .name = "SNS_PP1050", |