This is hayes AT command test too for SIMCOM GSM/GPRS modules (tested with SIM90X, SIM300 and SIM800 believed also work). This is very early alpha test release and use at your own risk.
I am not a programmer but I am an engineer who wrote codes for need.
Developed by Visual Studio Express 2010 and .NET 4.0 (For winXP compatibility)
Last year, I developped a GSM base project with SIM908 module. Mostly, GSM and GPRS modules works with Hayes AT commands. (https://en.wikipedia.org/wiki/Hayes_command_set) This type of module can be interfaced by UART and can controlled functions such as call, SMS and others many. Any UART terminal like Putty, Hyper Terminal can be used for this but typing many commands re is a boring tasks in development. So, I developed this application with my own need and share with you now.
AT Tester main screen
Sample Connection diagram
Support the following AT commands.
AT AT command test
AT+CSQ GSM Signal strength
AT+CREG? Network Info
ATI Modem/Module informations
AT+GMR Hardware version
AT+GSV Firmware version
AT&F Modem reset
AT&W Configuration Save
AT+CPOWD=1 Power Off
ATD Voice Call
ATH HangUp Call
AT+CMGS SMS Sending
Also sending custom AT commands
receiving respond string from Modem and display in Hex format
How to run,
Connect PC and modules
Run ATester, choose COM port and speed, presses connect button.
Power up module. Will see “yyyyyyyyyy” like message when module is power up.
Press “AT” button, will see “OK” message in receive terminal is module is working.
Press “Signal” and “Network” buttons to check whether modem is associated with GSM network. Will show “+CSQ:22,0” for signal where 22 is signal quality (something liked bars in your handset). Higher number is indicated that strong in signal. For network, will show “+CREG: 1,1” “OK”. This means modem is associated with GSM network. Good to go.
Tips : Message reply with “OK” means command is corrected executed (not means it is worked). Message responds with “Error” indicates that there is error in command. Check details in AT command manual like this.
SMS Receiving Manny commands neet to add such as AT+CREG, AT+CGMI, AT+CGMM, AT+CGSN, AT+CGMR, AT+CIMI, AT+CPBR Decoding respond from modem (Some feedback string need to phrase for more understandable) GPS? Only for SIMXX8 modules GPRS support? Custom AT commands set editing and saving in config files for different modules.
I will add more commands and functions soon. Still tune.
We have seen how new Iphone shakes the market. How about low tech phones and how much a handset cab be cheap? Last year, I saw Bunnie’s blog post about a cheap $12 Gongkai handset from Mingtong Digital Mall in Shenzhen. Gongkai means “Open” in Chinese and it’s the term alternative of “Open Source”. Mingtong Digital Mall is one of the famous digital gadget’s malls from Shenzhen especially cheap and copy items. I wondered how these cheap handset could be sold in this low price when I saw his blog post.
I lived in Myanmar, yes a green land opened it’s door recently. The government released telecom sector and has given the two new operators, Telenor and Ooredoo. Just a clarification, some may don’t know how Myanmar telecom sector is squeezed before 2000. I bet you will wonder how much it will cost for a mobile SIM card before 2000. It was cost about $5000 (Please up your jaw, I am not kidding :D). In last decade, owning a mobile phone was a trade mark of being a “boss” in Myanmar. Most people used a public pay land lines phone booth in every sight of cites. Seem these will soon be a history. But for now, news operators are moving and it costs about only $1.5.
Have you ever seen people queuing for a cheap SIM card?
Yesterday, one of my colleagues showed me a GSM handset with a surprised price tag, 10000 MMK. It is about $10 (1$ = 986 MMK). I quickly checked specs and my curiosity leaded me to bought one. It is a normal low price GSM handset with basic functions. I saw many cheap China handset but non are not lower than $20. This is the cheapest handset I have ever seen. Note that Bunnie’s Gongkai Phone is $12 at China, main land but I bought my $10 phone from local retail shop from Mandalay, Myanmar. More surprising fact is that my friend told me wholesale price is >$9. If this is right, how much it will be the ground cost of these handset in it’ts origin, China!! Unbelievable. Here is my cheapo handset. It is just ordinary phone but specs are even a little higher than Bunnie’s phone come with a box, handset, a battery, charger and a hands free earpiece.
The spec and functions listed on the box,
Touch
FM Radio
Music Player
Video player, recorder
MicroSD
Camera
Bluetooth
Multi languages
1.8″ Display
Dual SIM (Dual standby) , Stereo Speaker (Really, only one Speaker), Games
Frequency : GSM 900/1800 optional 850/9001800/1900
Multi Media : MP3/MP4/3GP/FM Radio / Bluetooth Camera 0.3 Mega Pixels
Multi Function Torch : Alarm ,Calendar ,Calculator ,Audio recorder ,Video recorder
Flash Card Support : T-Flash Card Max support to 8GB
Languages Multi language : Arabic,French,Turkish, Thai,Vietnam,Russian, English, Hindi, Indonesian, Spanish etc
I installed battery, SIM and power up the phone.
Tested basic functions call, menu, camera, FM etc.
– FM
– It supports Java.
It even include Myanmar language support. Changed and tested it but some menu were not properly show 🙂 .
Finally, I teared down to check how these cheapo was made.
Just removed 4 x small screws, everything disassembled.
Other are usual parts such as speaker, mic, SIM holder, SD slot, small camera, FM antenna and 2 x LEDs for torch. The phone is controlled by all in one chip. The back side Speaker housing is attached with multi-band antenna.
There is a EMI shield which covered the chip but google infos and some partially label can able to guess me the main chip. It is RDA8851 from RDA Microelectronics, one of chip manufacturer from China. In short, it’s all in one chip which doo everything for phone such as baseband, interface, Bluetooth, FM, camera, Flash (32Mb build in), UART, SPI, I2C etc. Here is the links to chip datasheet.
Firmware is Mstar from MStar Semiconductor, Taiwan . From Wiki , MStar is often referred as “Little-M” in Chinese community, as a contrary part of the bigger company “Big-M”, MediaTek.
– The only weakness of this phone (in comparable this price) is it’s charger. I also opened and checked the charger design. It voids all of safety rules. Manufacturer should include a more safe charger with a buck. The stock charger is one of the simplest and reduced version without any protection of it’s line. The design includes 13001 NPN Epitaxial Silicon Transistor, 1 IN4001 diode rectifier, small SMPS transformer, 5V zener, 3 capacitors and some resistors, that’s all. The output voltage is about 6V.
Final thought:
– First, I don’t expect much from this phone but the price is really amazed for me. It is a bare phone without no contract and unlocked. It exported from china to Myanmar. What will be local retail price and how much it can be lower?
– The cost of the phone is the parts and production costs plus a little export costs. There will be absolutely NO licensing, copy cats fee 🙂 and seem no certification.
– Everybody talks about SAR. But I think the RDA chip can take care of this in a basic level. The package label state that SAR Head : 0.342 W/Kg(1g) and body : 0.429 W/Kg (1g).
– I know that designing a mobile phone is not that hard. I designed my own DIY mobile phone recently with a basic functions like this phone with the same LCD. Even LCD it self costs about $6.4 in some ebay retail shops. What will be the lowest bargain price of this LCD? (I believe the LCD must be the most value part in this phone. Any idea?)
– For the chip, I don’t know how much cost for this RDA chip in volume and in retail. Bunnie said that MT6250 chip from his Gongkai Phone in retail price is $2.1.
– If someone knows about these, let me know and also share your thought.
Last :
Again, it is not rocket science to build a mobile phone. This is my DIY GSM mobile phone prototype which I recently developed for fun and hobby. Some basic functions such as call, sms, GPS are done and still working for a complete prototype. But, you may not defeat China at least in quantity and cost :D. Thanks for visiting.
Oakkar7, another Blog 