Agilent E3633A as Step Voltage Source using RS-232

Here is very small and simple program to use Agilent E3633A as step voltage source. I used LabView to get the same functionality before. But it took almost a week to complete it. With serial command it only took me only 2 hours. I didn't know it can be that easy. Here I started with 8V and 0.5mA. The voltage is then step down at 0.004V after every 50 seconds. To run this,

1. Copy the following code in a text file and save the test file with ttl extension.
2. Connect the Agilent E3633A with DB-9 cable or serial cable and power it on.
3. open Tera Term in serial connection.
4. Click Control-> Macro and load the file you saved.

You show see that the output voltage of E3633A is changed to 8V and after every 50s the voltage is falling 0.004V.

; Agilent E3633A Step Voltage ; By Obaej Tareq ; Tera Term setup -> Click Setup -> Terminal. ; Set Transmit: CR+LF and check Local echo. Baud rate 9600, Parity none, stop 1 bit. sendln "SYST:REM" sendln "APPL 8, 0.5" sendln "OUTP ON" mpause 5000 for i 1 251 mpause 30000 sendln "VOLT:STEP 0.004" sendln "VOLT DOWN" next

Place I want to travel

TI CC3000 WiFi and ThingSpeak - Online Weather Station

Introduction

The CC3000 chip from Texas Instruments is an amazing module for embedded application. When it first came out, every body got very excited. However, over the year, it appears to be an difficult module to work with. After lots of firmware update, now it appears to be more workable than before. 

In this project, I am using CC3000 (firmware v1.32 - Patch 1.14 why TI??) with Arduino Uno. I used Arafruit host library and ThingSpeak service for online interfacing. The similar application was developed by M.Schwartz and  was posted in Adafruit learning center. In that tutorial, he used Xively service for online interfacing. To me it seems that he was annoyed by the bugs in CC3000 and put watch dog timer in every steps to recover from the notorious CC3000 freezing issue. I also faced the same problem before. After the latest patch update, it seems that the CC3000 performance has been improved significantly. 

The circuit connections for WiFi and DHT11 temperature sensor remain same as Schwartz's design as shown here. For ThingSpeak account, please visit their website and open a free account. Log in to your account and open a new channel. In channel setting, most important part is, Field boxes. Check mark on the "add field" box to activate more channels. In my tutorial, I used only 2 channels and changed them as Temperature and Humidity. Next, the most important part is API Keys. Copy the "Write API Key" to write a data to the web server. Replace the "your api key"; in the code with your API key. Here is the Arduino sketch,

/*************************************************** * This is a sketch to use the online temperature and humidity sensor using Xively * * Actual code was written by Marco Schwartz for Open Home Automation * Updated by Obaej Tareq for Temperature and Humidity sensor. The "thingspaek" service has been used for web application. ****************************************************/ // Libraries #include <Adafruit_CC3000.h> #include <ccspi.h> #include <SPI.h> #include <string.h> #include<stdlib.h> #include "utility/debug.h" #include "DHT.h" #include <avr/wdt.h> // Define CC3000 chip pins #define ADAFRUIT_CC3000_IRQ 3 #define ADAFRUIT_CC3000_VBAT 5 #define ADAFRUIT_CC3000_CS 10 // temperature and humidity sensor #define DHTPIN 7 #define DHTTYPE DHT11 // Create CC3000 instances Adafruit_CC3000 cc3000 = Adafruit_CC3000(ADAFRUIT_CC3000_CS, ADAFRUIT_CC3000_IRQ, ADAFRUIT_CC3000_VBAT, SPI_CLOCK_DIV2); // you can change this clock speed // WLAN parameters //#define WLAN_SSID "yourSSID" //#define WLAN_PASS "wifi password (WPA2)" // Security can be WLAN_SEC_UNSEC, WLAN_SEC_WEP, WLAN_SEC_WPA or WLAN_SEC_WPA2 #define WLAN_SECURITY WLAN_SEC_WPA2 // Xively parameters // ThingSpeak Settings char thingSpeakAddress[] = "api.thingspeak.com"; String writeAPIKey = "your api key"; uint32_t ip; // Variable Setup long lastConnectionTime = 0; boolean lastConnected = false; int failedCounter = 0; // for themperature and humidity DHT dht(DHTPIN, DHTTYPE); void setup(void) { // Initialize Serial.begin(115200); ConnectWifi(); //// Connect with Wifi } void loop(void) { // Get data & transform to integers float h = dht.readHumidity(); float t = dht.readTemperature(); Serial.print("Temperature = "); Serial.println(t); Serial.print("Humidity = "); Serial.println(h); int temperature = (int) t; int humidity = (int) h; String tem=String(temperature, DEC); //Thingspeak only data stream is string type String hum=String(humidity, DEC); // Converting integer data to string Serial.print(F("api.thingspeak.com -> ")); while (ip == 0) { if (! cc3000.getHostByName("api.thingspeak.com", &ip)) { Serial.println(F("Couldn't resolve!, Restarting.....")); wdt_enable(WDTO_8S); // if host does not response wait 8 sec and restart while(1){} } delay(500); } cc3000.printIPdotsRev(ip); Serial.println(F("")); Adafruit_CC3000_Client client = cc3000.connectTCP(ip, 80); // Print Update Response to Serial Monitor if (client.available()) { char c = client.read(); Serial.print(c); } // Update ThingSpeak if(client.connected()) { // Send temperature and humidity data to Thingspeak site updateThingSpeak("1="+tem+"&2="+hum); delay(25000); // Thingspeak needs a 15s delay between 2 data stream. failedCounter=0; } else { Serial.println(F("Connection failed")); failedCounter++; if (failedCounter==10) { Serial.println(F("Connection failed for 10 times, Restarting......")); wdt_enable(WDTO_8S); // if 10 continuous data upload failed, restart host after 8s. while(1){} } } } void updateThingSpeak(String tsData) { Adafruit_CC3000_Client client = cc3000.connectTCP(ip, 80); Serial.println("Connecting to ThingSpeak..."); Serial.println("Sending Data"); client.print("POST /update HTTP/1.1\n"); client.print("Host: api.thingspeak.com\n"); client.print("Connection: close\n"); client.print("X-THINGSPEAKAPIKEY: "+writeAPIKey+"\n"); client.print("Content-Type: application/x-www-form-urlencoded\n"); client.print("Content-Length: "); client.print(tsData.length()); client.print("\n\n"); client.print(tsData); Serial.println(F("Done")); Serial.println(F("Waiting 30 sec for next sending")); } void ConnectWifi(){ Serial.println(F("\nInitializing...")); if (!cc3000.begin()) { Serial.println(F("Couldn't begin()! Check your wiring?")); while(1); } // Connect to WiFi network cc3000.connectToAP(WLAN_SSID, WLAN_PASS, WLAN_SECURITY); Serial.println(F("Connected!")); /* Wait for DHCP to complete */ Serial.println(F("Request DHCP")); while (!cc3000.checkDHCP()) { delay(100); } }

Picture: 

Here is my sensor reading in ThingSpeak website.