ChibiOS 2.6.8, until I can figure out where to get it from git.

firmware/chibios/testhal/STM32F1xx/I2C/tmp75.c

@@ -0,0 +1,60 @@
+/*
+    ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+/**
+ * TMP75 is most simple I2C device in our case. It is already useful with
+ * default settings after powerup.
+ * You only must read 2 sequential bytes from it.
+ */
+
+#include <stdlib.h>
+
+#include "ch.h"
+#include "hal.h"
+
+#include "tmp75.h"
+
+
+/* input buffer */
+static uint8_t tmp75_rx_data[TMP75_RX_DEPTH];
+
+/* temperature value */
+static int16_t temperature = 0;
+
+static i2cflags_t errors = 0;
+
+#define tmp75_addr 0b1001000
+
+/* This is main function. */
+void request_temperature(void){
+  int16_t t_int = 0, t_frac = 0;
+  msg_t status = RDY_OK;
+  systime_t tmo = MS2ST(4);
+
+  i2cAcquireBus(&I2CD1);
+  status = i2cMasterReceiveTimeout(&I2CD1, tmp75_addr, tmp75_rx_data, 2, tmo);
+  i2cReleaseBus(&I2CD1);
+
+  if (status != RDY_OK){
+    errors = i2cGetErrors(&I2CD1);
+  }
+
+  t_int = tmp75_rx_data[0] * 100;
+  t_frac = (tmp75_rx_data[1] * 100) >> 8;
+  temperature = t_int + t_frac;
+}
+
+