summaryrefslogtreecommitdiffstats
path: root/README.md
diff options
context:
space:
mode:
authorjoeycastillo <joeycastillo@utexas.edu>2021-08-25 23:50:51 -0600
committerGitHub <noreply@github.com>2021-08-25 23:50:51 -0600
commitef9736a3c96d3e345b7184c678921b5243bbbb99 (patch)
tree60e553db25db9d21525640632c5de9c1b7021336 /README.md
parent2c6c60537286cc26b87f3168b0545600d666aae2 (diff)
downloadSensor-Watch-ef9736a3c96d3e345b7184c678921b5243bbbb99.tar.gz
Sensor-Watch-ef9736a3c96d3e345b7184c678921b5243bbbb99.tar.bz2
Sensor-Watch-ef9736a3c96d3e345b7184c678921b5243bbbb99.zip
Update README with some clarifications
Diffstat (limited to 'README.md')
-rw-r--r--README.md20
1 files changed, 11 insertions, 9 deletions
diff --git a/README.md b/README.md
index de9676df..c13103e1 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ Features:
* ARM Cortex M0+ microcontroller
* 32KHz crystal for real-time clock with alarm function
* Ten digit segment LCD, plus five indicator segments
-* Three interrupt capable buttons (one can wake from backup mode)
+* Three interrupt capable buttons
* Red / green PWM’able LED backlight
* Optional piezo buzzer (requires some light soldering)
* On-board USB Micro B connector
@@ -18,16 +18,18 @@ Features:
![image](/images/sensor-board.png)
-You may have noticed that there are no sensors on this board. That is by design: rather than pick sensors for you, the goal is to add a tiny flexible PCB with the sensors YOU want, and interface them over the nine-pin connector. In addition to providing ~3V power and ground, the connector provides the following options for connectivity:
+You may have noticed that there are no sensors on this board. That is by design: rather than pick sensors for you, the goal is to add a tiny flexible PCB with the sensors YOU want, and interface them over the nine-pin connector. The connector provides the following options for power and connectivity:
-* An I2C interface with built-in pull-ups
+* 3V power (nominal voltage from a CR2016 coin cell, can drop to ~2.7V)
+* An I²C interface with built-in pull-up resistors
* Five general purpose IO pins, which can be configured as:
- * Three analog inputs and two digital IO
- * An SPI device + one analog / GPIO pin
- * One UART + 3 GPIO
- * Five digital IO pins
- * Four PWM pins on two independent TC channels
- * Five interrupt pins (two can wake from backup mode)
+ * Five analog inputs
+ * Five interrupt-capable digital inputs, with internal pull-up or pull-down resistors
+ * Five digital outputs
+ * SPI controller (with one spare analog / GPIO pin leftover)
+ * One UART TX/RX pair (with three GPIO leftover)
+ * Up to four PWM pins on two independent TC instances
+ * Two external wake inputs that can wake from the ultra-low-power BACKUP mode
![image](/images/sensor-board-pinout.png)