From 98af7d3d62c20f8b499debec784ab28178528c15 Mon Sep 17 00:00:00 2001
From: Schorcht <gunar@schorcht.net>
Date: Mon, 1 Oct 2018 09:04:31 +0200
Subject: [PATCH] drivers: add driver for CCS811 gas sensor
---
drivers/ccs811/ccs811_saul.c | 43 ++++++++++++++++++------------------
1 file changed, 21 insertions(+), 22 deletions(-)
diff --git a/drivers/ccs811/ccs811_saul.c b/drivers/ccs811/ccs811_saul.c
index 8460d1fdf8..b1fab26857 100644
--- a/drivers/ccs811/ccs811_saul.c
+++ b/drivers/ccs811/ccs811_saul.c
@@ -23,45 +23,44 @@
#include "ccs811.h"
-static uint16_t _iaq_tvoc = 0;
-static uint16_t _iaq_eco2 = 0;
+static bool _data_ready = false;
-static int read(const ccs811_t *dev)
+static int read(const ccs811_t *dev, uint16_t *iaq_tvoc, uint16_t *iaq_eco2)
{
- /* check whether new data can be read */
- int res = ccs811_data_ready((ccs811_t *)dev);
-
- if (res != CCS811_OK) {
- return res;
+ if (!_data_ready) {
+ /* if no data were ready yet, test for new data */
+ if (ccs811_data_ready((ccs811_t *)dev) == CCS811_OK) {
+ _data_ready = true;
+ }
+ else {
+ return -ECANCELED;
+ }
}
- /* read new data and save them to local storage */
- return ccs811_read_iaq((ccs811_t *)dev, &_iaq_tvoc, &_iaq_eco2, 0, 0);
+ int res = ccs811_read_iaq((ccs811_t *)dev, iaq_tvoc, iaq_eco2, NULL, NULL);
+
+ /* in case of CCS811_ERROR_NO_NEW_DATA last valid data are returned */
+ return (res == CCS811_OK ||
+ res == -CCS811_ERROR_NO_NEW_DATA) ? 0 : -ECANCELED;
}
static int read_tvoc(const void *dev, phydat_t *res)
{
- /* read new data if available */
- read(dev);
-
- /* fill data from local storage */
- res->val[0] = _iaq_tvoc;
+ if (read(dev, (uint16_t*)&res->val[0], NULL) != 0) {
+ return -ECANCELED;
+ }
res->unit = UNIT_PPB;
res->scale = 0;
-
return 1;
}
static int read_eco2(const void *dev, phydat_t *res)
{
- /* read new data if available */
- read(dev);
-
- /* fill data from local storage */
- res->val[0] = _iaq_eco2;
+ if (read(dev, NULL, (uint16_t*)&res->val[0]) != 0) {
+ return -ECANCELED;
+ }
res->unit = UNIT_PPM;
res->scale = 0;
-
return 1;
}
--
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