MMDVM hotspot – hardware network switch

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Several months ago, John VK4JWT asked me if I knew of a way to switch his JumbSpot between Brandmeister and DMR Marc using some sort of physical switch. John was interested in this feature, because he does a lot of mobile operation and it would be much easier to be able to flick a switch on the hotspot, when driving along in he car, than it would be to mess around with different channels … Read More

TTGO T5 eInk display – update

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In the last few days I’ve been attempting to resolve a major design fault on the TTGo T5 eInk display board, where the battery management chip (IP5306) was completely turning off the power to the ESP32, and the other chips, when I put the ESP32 into deep sleep mode.   The problem is a design fault, and is primarily because the battery management chip (IP5306) is designed for “power bank” devices, where a LiPo … Read More

TTGO T5 2.9inch e-Ink display with ESP32 MCU

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e-Ink, also known as e-Paper displays have become a lot more affordable in the last year, with several Chinese companies selling modules with or without a built in mircocontroller, so I finally decided to buy a few to test.   One of the more interesting display + micro-controller modules is the “TTGO T5” module, which features a ESP32 WiFi processor, and a 2.9 inch e-Ink display, 3 buttons (4 if you include the “reset” … Read More

LiPo battery charging from a 1W 5V solar panel

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In my previous post, I reviewed some “5V 1W” solar panels, with a view to using them to power some IoT devices, and in this post I’ll show my experiments and conclusions about using the panel to charge the battery. LiPo cells have specific charging and usage requirements so that they don’t get damaged.  For charging the basic principal is that they require both constant current and then constant voltage charging. They also should … Read More

Cheap “5V 1W” solar panel

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I’ve been investigating solar power options for some external monitoring devices, so I invested in three (3)  “5V 1W” solar panels from eBay,  the amazing price of  $1.69 AUD each (around $1.20 USD or £1 UK), not really knowing what to expect.     When the panels arrived, the first thing I noticed as that the solar collector on each of them, didn’t quite look the same.     Also, one of them had … Read More

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