Hello again everyone, In addition to the USB to dual UART adapter covered in my previous post, the other accessory needed for working with FCDEV3B boards is a 3.6 VDC power supply. It seems that most GSM modem evaluation boards (for GTM900 etc) made by parties other than TI and FreeCalypso implement an arrangement where external power input to the board is 5V nominal, and there is an on-board LDO regulator that takes this 5V power input and produces some battery-emulating voltage (from 3.5 to 4.2 V depending on who designed each given board) to feed to the actual GSM chipset or module - but on our FCDEV3B I implemented a different approach, the same one which TI had on their own historical development boards: the power input to the board goes directly to the VBAT rail, without any on-board regulators or converters, and the user is responsible for supplying battery-emulating power, 3.6 VDC nominal recommended.
It appears that some people have been unhappy with my choice of board powering arrangement, for the obvious reason that power supplies putting out 3.6 VDC are much less common than 5V ones. My original intent was to supply an ultra-compact universal AC to 3.6 VDC power adapter with every FC development board kit, but the problem was that I could not find any inexpensive ones. The only such adapter I did have to offer was expensive, putting prospective users in a difficult position of either paying for an expensive PSU or having to provide their own supply of an "oddball" DC voltage with high current rating to support GSM Tx bursts. As of yesterday this PSU accessory problem is finally solved: a month ago I ordered a batch of 100 new power adapters custom-made for us, and they arrived from China yesterday. They look totally professional, no different from a power adapter you would get for a laptop or whatever, but they put out 3.6 VDC with 2.2 A rating just like our previous scarce adapters, and they are just as compact. I will ship them fitted with Weidmuller connectors that plug into our dev boards, and the total cost (before shipping) of one adapter is about $7, very inexpensive. If anyone has an FCDEV3B board but has no good power supply for it, please ask, and I can send you one of our new power adapters for the cost of shipping from USA. No charge for the adapter itself - the adapter cost is negligible compared to what you paid for the FCDEV3B. All future kits will have these PSUs included as a standard accessory at no extra cost. Hasta la Victoria, Siempre, Mychaela aka The Mother _______________________________________________ Community mailing list Community@freecalypso.org https://www.freecalypso.org/mailman/listinfo/community