回复： Perfect module (D751749ZHH)

[songbosi]

Hi M~,


1) I havn't test it's nIBOOT pin, I have dump the flash with gtm900-b with your fc tool
    https://app.2sim.cn/gsm/gtm_full.bin


2) I modify this for 900/1800 switching,  using gta02 OsmocomBB
 
#define	ASM_VC1		TSPACT(1)	
 
#define	ASM_VC2		TSPACT(2)

     https://app.2sim.cn/gsm/rffe_gta0x_triband.c



3) I would ship this module to US with fpc connector, you can just using an USB to UART adapter to get it work with PC
    https://app.2sim.cn/gsm/fpc.jpg




------------------ 原始邮件 ------------------
发件人: "Mychaela Falconia"<mychaela.falconia at gmail.com>;
发送时间: 2019年5月29日(星期三) 凌晨4:28
收件人: "songbosi"<79543015 at qq.com>;
抄送: "community"<community at freecalypso.org>;
主题: Re: Perfect module (D751749ZHH)



Hi again Songbosi,

Thanks for the documentation - that GTM900-B module does look
interesting.  Given that you've got OsmocomBB running on it, you must
have already done a fair bit of reverse engineering on this module in
order to get that far, so I hope you don't mind if I ask you to share
some of your technical findings.  Let us start with a few basics:

1) Does this module have the Calypso boot ROM enabled via nIBOOT pin
strapping?  In other words, is it possible to gain code download
access via tools like fc-loadtool or osmocon, or is JTAG the only way?

2) How are various GPIO and RF control signals wired?  Which TSPEN
signal goes to the Rita transceiver (TSPEN2 like on most Calypso
designs, or TSPEN1 like on the Pirelli DP-L10, or other?) and which
TSPACT signal controls what?

You also wrote on the OsmocomBB mailing list:

> I have about 500 pcs left, I could sell them with $15/pcs

Your price is very reasonable and I may be interested in a few to play
with, but do you have any kind of breakout board for easy
experimentation with these modules?

M~