Hi All, I’m Hirano working as a Hardware engineer in the Development Division. At Aptpod, we have some clients who are using our products for measurements abroad. And sometimes they face different kinds of problems and taking measurements abroad seems to be a bit complicated. This year, I planned to take a long 28-day vacation to visit my family in Ivory Coast and Benin. So, I wonder how it would be to use one of our products during my trip to Africa and share my experience with my colleagues and (why not) with you too reader here...
Preparation
System Construction
Data I would like to Measure and Choice of the edge computer
Telecommunication Restrictions Due to Radio Law Regulation
Devices Structure
Drive report of the trip
Drive around Abidjan Plateau
Trip Abidjan(CI) to Ouidah(Benin)
Trip Ouidah to Abidjan
Introspection Points
Preparation
System Construction
Data I would like to Measure and Choice of the edge computer
Here are the kind of data I would like to share: Video, Audio, CAN, GPS, Environment temperature and humidity, etc… Our hardware available to customers now is the EDGEPLANT T1. But for this trip, I decided to test our currently on-developing edge computer based on Raspberry Pi.
This edge is less powerful than the T1 but it is smaller, lighter, and easier to carry around. The hardware is enough to fit better our demand by providing an LTE module with a GPS incorporated, a 3D accelerometer and 3D gyrometer, 1 channel of CAN Bus, 4 entries for ADC, and 2 USB ports that could serve for the Video and Audio Data…
Device we would like to use
Telecommunication Restrictions Due to Radio Law Regulation
The first problem we encountered in our design was the Radio Law Regulation. Indeed, as in Japan where all products utilizing radio spectrum are to conform with the Japan Radio Law, we would need to use LTE modules and antennas to conform to the Radio Law and certificate our device with the ARTCI (Ivory Coast), the NCA(Ghana) and the ARCEP(Togo / Benin) to use a radio communication in these countries. Certification of a device can be costly and time-consuming. It is a necessity if we want to enter our product in a market. But in this kind of “one-time measurement”, we need a non-costly and easier way. We came up with the idea of using pocket Wi-Fi to connect to the network and get rid of the LTE module inside the edge.
In Ivory Coast, we have two major Telecom companies, Orange and MTN (World Information and Communication Circumstances from Ministry of Internal Affairs and Communications). According to locals, Orange has the best rural coverage and helpful customer service while MTN is also available in Benin, Togo, and Ghana. We decided to use MTN to cover the trip inside Ivory Coast and the inter-regional one from Ivory Coast to Benin because we would be able to use the same pocket-wifi ZLT M30S (LTE up 50Mbps, CDMA 5.76Mbps). We just need to insert one 4G SIM from MTN to connect to the internet. Theoretically, we can also send out data by connecting our edge computer through the USB port of the pocket-wifi.
Pocket Wifi ZLT M30S
Our GPS being incorporated with the LTE module, we need now to find another solution for the GPS and end up choosing a USB to GPS receiver. Some USB devices don’t work automatically on Raspi because the driver may not be available in our Linux Operating system via the kernel. We tested different devices that we had experienced with the EDGEPLANT T1 and ended up choosing the USB-GNSS receiver GU-902-MGG.
Now that we have resolved our problem of telecommunication, we can work on the different devices we would like to connect to the edge.
Devices Structure
As we wrote above, the edge computer can handle an IMU (accelerometer and gyrometer), one CAN channel, 4 channels for ADC, and 2 USB ports. To connect to the ADC, we will use an analog sensor board where we measure the supplied voltage and the current in the edge, the temperature, and the humidity. For the USB ports, in addition to the camera and the microphone, we now have to handle also the USB-Wifi and the USB-GNSS. We therefore add a USB Hub ST7200USBM ( USB2.0 7 Ports) to connect the extra devices. The system looks now as follows.
Device Structure