stephanebachelier · December 9, 2023 01:24 · Sep 3, 2016 · Dec 13, 2015 · Dec 13, 2015 · Dec 13, 2015
diff --git a/spi_dump.js b/spi_dump.js
@@ -1,4 +1,5 @@
 // NodeJS SPI Dump for MCP3008 - Created by Mikael Levén
+// Original https://gist.github.com/mikaelleven/c3db08ae7837eb3c8698
 var rpio = require('rpio');
 
 rpio.spiBegin();
@@ -15,25 +16,27 @@ for (var channelHeader = 0; channelHeader <= 7; channelHeader++) {
 setInterval(function() {
     for (var channel = 0; channel <= 7; channel++) {
         // Prepare TX buffer [trigger byte = 0x01] [channel 0 = 0x80 (128)] [placeholder = 0x01]
-        var sendBuffer = new Buffer([0x01, (8 + channel << 4), 0x01]); 
+        var txBuffer = new Buffer([0x01, (8 + channel << 4), 0x01]);
+        var rxBuffer = new Buffer(txBuffer.byteLength);
 
-        var recieveBuffer = rpio.spiTransfer(sendBuffer, sendBuffer.length); // Send TX buffer and recieve RX buffer
+        rpio.spiTransfer(txBuffer, rxBuffer, txBuffer.length); // Send TX buffer and recieve RX buffer
 
-        // Extract value from output buffer. Ignore first byte. 
-        var junk = recieveBuffer[0],
-            MSB = recieveBuffer[1],
-            LSB = recieveBuffer[2];
+        // Extract value from output buffer. Ignore first byte.
+        var junk = rxBuffer[0],
+            MSB = rxBuffer[1],
+            LSB = rxBuffer[2];
 
-        // Ignore first six bits of MSB, bit shift MSB 8 positions and 
+        // Ignore first six bits of MSB, bit shift MSB 8 positions and
         // finally combine LSB and MSB to get a full 10 bit value
-        var value = ((MSB & 3) << 8) + LSB; 
+        var value = ((MSB & 3) << 8) + LSB;
 
         process.stdout.write(value.toString() + (channel == 7 ? '\n' : '\t'));
     };
 }, 1000);
 
 
 process.on('SIGTERM', function () {
+
     process.exit(0);
 });
 

diff --git a/readme.md b/readme.md
@@ -5,7 +5,7 @@ This is a simple script that reads all eight analog channels of an MCP3008 each
 
 I created this script to ease debugging of the MCP3008 ADC connected to my Raspberry Pi.
 
-If you need to troubleshoot SPI your can check out my guide how to test SPI using loopback "debug mode" https://mikaelleven.wordpress.com/2015/12/10/troubleshooting-spi-on-raspberry-pi-nodejs/.
+If you need to troubleshoot the SPI connection in itself you can check out my guide how to test SPI through the loopback "debug mode" https://mikaelleven.wordpress.com/2015/12/10/troubleshooting-spi-on-raspberry-pi-nodejs/.
 
 ### Installation
 

diff --git a/readme.md b/readme.md
@@ -5,15 +5,17 @@ This is a simple script that reads all eight analog channels of an MCP3008 each
 
 I created this script to ease debugging of the MCP3008 ADC connected to my Raspberry Pi.
 
+If you need to troubleshoot SPI your can check out my guide how to test SPI using loopback "debug mode" https://mikaelleven.wordpress.com/2015/12/10/troubleshooting-spi-on-raspberry-pi-nodejs/.
+
 ### Installation
 
+Download this gist and run the following command
 ```sh
 npm install rpio
 ```
 
 ### Usage
 
-```js
-xx
-
+```sh
+sudo node spi_dump.js
 ```
diff --git a/spi_dump.js b/spi_dump.js
@@ -1 +1,48 @@
-Dump
+// NodeJS SPI Dump for MCP3008 - Created by Mikael Levén
+var rpio = require('rpio');
+
+rpio.spiBegin();
+//rpio.spiChipSelect(0);                  /* Use CE0 (slave 0) */
+//rpio.spiSetCSPolarity(0, rpio.LOW);    /* Commonly chip enable (CE) pins are active low, and this is the default. */
+//rpio.spiSetClockDivider(256);           /* MCP3008 max is ~1MHz, 256 == 0.98MHz */
+//rpio.spiSetDataMode(0);
+
+process.stdout.write('\x1b[36m');
+for (var channelHeader = 0; channelHeader <= 7; channelHeader++) {
+    process.stdout.write('ch' + channelHeader.toString() + (channelHeader == 7 ? '\x1b[0m\n' : '\t'));
+}
+
+setInterval(function() {
+    for (var channel = 0; channel <= 7; channel++) {
+        // Prepare TX buffer [trigger byte = 0x01] [channel 0 = 0x80 (128)] [placeholder = 0x01]
+        var sendBuffer = new Buffer([0x01, (8 + channel << 4), 0x01]); 
+
+        var recieveBuffer = rpio.spiTransfer(sendBuffer, sendBuffer.length); // Send TX buffer and recieve RX buffer
+
+        // Extract value from output buffer. Ignore first byte. 
+        var junk = recieveBuffer[0],
+            MSB = recieveBuffer[1],
+            LSB = recieveBuffer[2];
+
+        // Ignore first six bits of MSB, bit shift MSB 8 positions and 
+        // finally combine LSB and MSB to get a full 10 bit value
+        var value = ((MSB & 3) << 8) + LSB; 
+
+        process.stdout.write(value.toString() + (channel == 7 ? '\n' : '\t'));
+    };
+}, 1000);
+
+
+process.on('SIGTERM', function () {
+    process.exit(0);
+});
+
+process.on('SIGINT', function () {
+    process.exit(0);
+});
+
+process.on('exit', function () {
+    console.log('\nShutting down, performing GPIO cleanup');
+    rpio.spiEnd();
+    process.exit(0);
+});
diff --git a/readme.md b/readme.md
@@ -1,20 +1,19 @@
 NodeJS SPI Dump for MCP3008 
 ===========================
 
-This is a simple and easy to use **SPI** module for **node.js**.
+This is a simple script that reads all eight analog channels of an MCP3008 each second and outputs the result to the console. 
 
-I created this script to ease debugging of analog values from a MCP3008 ADC connected to my Raspberry Pi. 
+I created this script to ease debugging of the MCP3008 ADC connected to my Raspberry Pi.
 
 ### Installation
 
 ```sh
-npm install simplespi
+npm install rpio
 ```
 
 ### Usage
 
 ```js
-var simplespi = require( "simplespi" );
+xx
 
-var response = simplespi.send( "AA00FF", "/dev/spidev0.1" );
 ```
diff --git a/readme.md b/readme.md
@@ -1 +1,20 @@
-Lorem
+NodeJS SPI Dump for MCP3008 
+===========================
+
+This is a simple and easy to use **SPI** module for **node.js**.
+
+I created this script to ease debugging of analog values from a MCP3008 ADC connected to my Raspberry Pi. 
+
+### Installation
+
+```sh
+npm install simplespi
+```
+
+### Usage
+
+```js
+var simplespi = require( "simplespi" );
+
+var response = simplespi.send( "AA00FF", "/dev/spidev0.1" );
+```
diff --git a/readme.md b/readme.md
@@ -0,0 +1 @@
+Lorem
diff --git a/spi_dump.js b/spi_dump.js
@@ -0,0 +1 @@
+Dump
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