Don’t use these battery charger chips from TI and MICROCHIP !

This post is about some of the design mistakes which I did in designing my GPS trackers and this mistake is associated with selection for the battery charger chips. I am sharing this so that you will be careful and aware when choosing the battery charger chips for your GSM based applications. 

GSM Network time synchronization for RTC using AT+CLTS command

In this post i will show you guys how we can automatically synchronize the RTC of our GSM module with the network time. This method is very useful if we are using a board that doesnt have battery backup present on it. Once the GSM module RTC is synchronized, we can also sync the MCU RTC and also any external RTC if we are using one.

Don’t use Freescale made NXP chips – EOL issues after acquisition

I had been extensively using the MMA8652 accelerometer in my design because of its small size, easy interface and low cost. The accelerometer fits the bill correctly in most of my designs. It has appeared in many of my projects including my VALTRACK-V2 GSM/GPS tracker. But its no longer easily available after the merger of Freescale Semiconductors with NXP Semiconductors. 

Learn, Why you should choose a GNSS module over a GPS module?

In this post we will see why we should select a GNSS module over a GPS only module. There are a lot of Navigation module manufacturers offering GPS and GNSS modules. The GPS modules are always cheaper than the GNSS modules because they support only one satellite constellation and GNSS modules support multiple countries satellite constellations. 

Designing a DTMF based Home automation system – GSM | Relay control

It had been a long time since i wanted to make a building automation system. In fact it was the first product i ever dream’t of making. Time passed and i didn’t quite find the time and interest to venture into it as i felt that building automation is a old concept and there are too many players doing the same stuff. 

Arduino MQTT Library with Publish and Subscribe example

In this post you will find the Arduino MQTT libraries which i used in my tutorial where i showed how to form MQTT packets and also how to send MQTT Publish and Subscribe packets to free MQTT brokers like CloudMQTT, Adafruit.io and Mosquitto.org. Go ahead and download the code and have fun experimenting. 

Low cost 3G modules for using in Australia | UMTS/HSDPA modems

Hello guys, In this post we will see a list of 3G modules that work with Australian 3G network providers. Unlike other countries, the Australian networks use a slightly different frequency bands, especially Telstra, the leading network provider in Australia. Almost all other carriers, like Optus,,Virgin Mobiles and Vodafone follow standard European frequency bands.

Zoho mail is not FREE anymore – Looking for alternatives

This post is coming out of frustration caused by ZOHO mail. The free mail hosting provider, who also provides paid email hosting plans has limited the free email hosting service access to webmail only, which means, we cant access the mail from outside clients like Microsoft outlook. Earlier i used Zoho mail for accessing one of my domains email since i only had a few users and Zoho mail was the best possible solution at that time.

SIM868 vs SIM808 – Differences and Comparison | Which to choose?

In this post we will learn the differences between the old GSM+GNSS enabled combo modules SIM808 and the new module SIM868. The SIM868 is a newer module with a very small form factor which keeps all the benefits of SIM808 and extends the features in some areas.  Both the modules are quad band modules and this post should enable you to make the right selection.