Challenges in custom m2m hardware design, manufacture, test and installation

Vending machines dispense snacks on insertion of required currency or credit. In a press release dated January 21st 2014, Kheda District Milk Producers’ Union, popularly known as Amul Dairy, announced that it will start selling milk through “Any Time Milk” vending machines. I wouldn’t be too surprised if Coffee Day, Britannia and Parle-G follow suit. But, it’s not easy to sell a perishable product through a vending machine.

Assume this vending machine is located in a village or even a huge apartment complex. Suddenly a tourist bus or a marriage party makes an unscheduled stop and used up a lot of the milk packets. Will it sit empty? How is the operator going to know? If this machine sat outside a store and customers only bought milk when the store was closed. Should the store owner really load all 150 packets and risk loss? How is the operator going to know how much to buy?

While all this was happening in India, I was working on a vending machine telemetry device 10000 miles away at Blue Sparq, Inc located in Southwest Florida, USA. The device transmits sales and inventory data to the cloud via WIFI, CDMA or GSM networks. Now an operator using a PC/cell phone app can decide when to replenish the inventory of their vending machines. This device could be the answer to all the questions raised earlier.

Since these devices transfer meaningful data from one machine to another, they are called M2M devices. From my experience I can say that, designing such an M2M device is not a joke. For instance, let us consider the power source. The vending machine is wall mounted and it can provide power to our M2M device. But, what if there is a power outage? What if it lasts for more than a couple of hours? One way to deal with this situation is by having a battery backup. But, adding a battery will add cost to this small unit. If this added cost is unacceptable, a simpler solution is to send a code to the server telling it’s still online and working fine. If this heartbeat code is not received for a period of time, the operator needs to be concerned about possible power outage.

Another challenge is troubleshooting these M2M devices. Most of these devices do not have a screen. This makes it very difficult to troubleshoot the device once they are installed. The operator may not be very technically savvy. So, there must be a simple and quick way to tell if the device is operating correctly or not. Something as simple as a blinking LED will go a long way. There must be a way to quickly login to the device and check for issues. One solution to this would be to have a simple web server that can show the status of the complete device and run simple commands to help troubleshoot, maintain and operate the device.

Vending machines need to operate forever. Once an operator buys it he expects it to work well for a long period of time. Same is the expectation for every device in it. However, the kind and frequency of requested data may change. For example, the device provider may want to cut costs and reduce the number of heartbeat codes transmitted at a later stage. An over the air firmware upgrade feature is a key requirement under such cases.

A major challenge during the manufacturing stage is the testing of produced devices. Automated test equipment needs to developed, that can upload code, provide test data and confirm the produced device is transferring data to a test server. This way we can ensure the customer is receiving quality devices to use in his machine.

Communication protocols, security and Mechanical design challenges deserve their own blogs.

The growth in cellular network coverage is already allowing the use of GPS trackers, MPOS terminals and other M2M devices throughout the world. A custom product design and manufacturing house that has experience, technical expertise and understanding of the marketplace would be an ideal partner to the likes of TCS, WIPRO, IDEA CELLULAR, Coffee Day to manufacture complete M2M solutions that can improve quality of life.

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