Comments for imsolidstate http://www.imsolidstate.com Always improving things... Tue, 20 Jul 2010 15:05:09 -0600 http://wordpress.org/?v=2.8.4 hourly 1 Comment on SMS remote control by imsolidstate http://www.imsolidstate.com/archives/708/comment-page-1#comment-2518 imsolidstate Tue, 20 Jul 2010 15:05:09 +0000 http://www.imsolidstate.com/?p=708#comment-2518 I looked into GSM modules, but I couldn't find any for cheap. The best deals are over at <a href="http://www.sparkfun.com/commerce/categories.php?c=66" rel="nofollow">Sparkfun</a>, but you're spending roughly $90 to get a module. The link you sent from mikroElektronika is just the breakout board for a module, you still have to buy the module. That's why I went with the cell phone, it's about twenty bucks. The PDU thing is a pain, so spending the money is probably worth it. I looked into GSM modules, but I couldn’t find any for cheap. The best deals are over at Sparkfun, but you’re spending roughly $90 to get a module. The link you sent from mikroElektronika is just the breakout board for a module, you still have to buy the module. That’s why I went with the cell phone, it’s about twenty bucks.
The PDU thing is a pain, so spending the money is probably worth it.

]]> Comment on SMS remote control by imsolidstate http://www.imsolidstate.com/archives/708/comment-page-1#comment-2517 imsolidstate Tue, 20 Jul 2010 14:56:54 +0000 http://www.imsolidstate.com/?p=708#comment-2517 Thanks, I'll fix that. The program never returns from the decode_sms() routine. Unfortunately, there's a lot that could go wrong there. I suspect one of my offsets to break up the PDU string is incorrect. I need to debug the code (I added a bunch of diagnostic LEDs for that purpose) but haven't had time due to other projects. Thanks for your help! Thanks, I’ll fix that. The program never returns from the decode_sms() routine. Unfortunately, there’s a lot that could go wrong there. I suspect one of my offsets to break up the PDU string is incorrect. I need to debug the code (I added a bunch of diagnostic LEDs for that purpose) but haven’t had time due to other projects. Thanks for your help!

]]> Comment on SMS remote control by Jon S http://www.imsolidstate.com/archives/708/comment-page-1#comment-2511 Jon S Tue, 20 Jul 2010 04:47:27 +0000 http://www.imsolidstate.com/?p=708#comment-2511 I would look into one of the GSM modules from Mikroelektronika. They connect thru serial link to your uC. http://www.mikroe.com/eng/categories/view/19/gsm-gprs-tools/ I've been eyeing some of their boards for GSM SMS capabilities. You just need to make sure that the specific module supports the SMS without being in PDU mode. The Telit GM862 supports SMS in Text mode. Although a downside is that it will probably cost more than the cellphone you bought. I would look into one of the GSM modules from Mikroelektronika. They connect thru serial link to your uC. http://www.mikroe.com/eng/categories/view/19/gsm-gprs-tools/

I’ve been eyeing some of their boards for GSM SMS capabilities. You just need to make sure that the specific module supports the SMS without being in PDU mode. The Telit GM862 supports SMS in Text mode. Although a downside is that it will probably cost more than the cellphone you bought.

]]> Comment on SMS remote control by Antoine http://www.imsolidstate.com/archives/708/comment-page-1#comment-2507 Antoine Tue, 20 Jul 2010 03:15:50 +0000 http://www.imsolidstate.com/?p=708#comment-2507 Hey, I quickly surveyed your program and found that when you are comparing strings such as in : message[0x01]=='e' & message[0x02]=='l' & message[0x03]=='a' & you are using a single ampersand which is the bitwise AND operator. You want the AND logical operator which is &&. I think your comparisons will still work, but they are dependent on a true being represented by the same value while the C standard defines true as not 0. Doing it this way probably leads to a faster comparison, but its risky. Otherwise, I cannot see what is wrong with it. It would help a lot if it was commented. You probably tried sending commands to the AVR using a computer's serial port or sniffing the contents or command from the cell-phone. Where does it stops working exactly? Hey,

I quickly surveyed your program and found that when you are comparing strings such as in :
message[0x01]==’e’ &
message[0x02]==’l’ &
message[0x03]==’a’ &

you are using a single ampersand which is the bitwise AND operator. You want the AND logical operator which is &&. I think your comparisons will still work, but they are dependent on a true being represented by the same value while the C standard defines true as not 0. Doing it this way probably leads to a faster comparison, but its risky.

Otherwise, I cannot see what is wrong with it. It would help a lot if it was commented.

You probably tried sending commands to the AVR using a computer’s serial port or sniffing the contents or command from the cell-phone. Where does it stops working exactly?

]]> Comment on My Photography by Flatbed scanner panoramic camera » imsolidstate http://www.imsolidstate.com/about/my-photography/comment-page-1#comment-2412 Flatbed scanner panoramic camera » imsolidstate Sat, 17 Jul 2010 02:25:48 +0000 http://www.imsolidstate.com/about/my-photography#comment-2412 [...] when they’re printed up big. I’m not new to panoramics, as I’ve done quite a few stitched sequences, as well as true panoramic film photography. A while back I was wondering if I could repurpose the [...] [...] when they’re printed up big. I’m not new to panoramics, as I’ve done quite a few stitched sequences, as well as true panoramic film photography. A while back I was wondering if I could repurpose the [...]

]]> Comment on 0.008″ PCB trace isolation on my CNC by imsolidstate http://www.imsolidstate.com/archives/476/comment-page-1#comment-1981 imsolidstate Wed, 23 Jun 2010 13:20:26 +0000 http://www.imsolidstate.com/?p=476#comment-1981 I'm not really sure, I've easily made upwards of a dozen boards and I'm still using the same cutter and set of drill bits. As for the drill bits I'm trying to use as much surface mount components as possible, so these days I'm mostly drilling vias. Resharpened carbide bits aren't too expensive anyway, you can get sets at drillbitcity.com or ebay. I’m not really sure, I’ve easily made upwards of a dozen boards and I’m still using the same cutter and set of drill bits. As for the drill bits I’m trying to use as much surface mount components as possible, so these days I’m mostly drilling vias. Resharpened carbide bits aren’t too expensive anyway, you can get sets at drillbitcity.com or ebay.

]]> Comment on 0.008″ PCB trace isolation on my CNC by Austin http://www.imsolidstate.com/archives/476/comment-page-1#comment-1979 Austin Wed, 23 Jun 2010 06:52:20 +0000 http://www.imsolidstate.com/?p=476#comment-1979 Hi. What is the lifetime (# of boards) of the drill bits? Also emailing this question. Hi. What is the lifetime (# of boards) of the drill bits? Also emailing this question.

]]> Comment on Moisture Meter for Plants by imsolidstate http://www.imsolidstate.com/archives/506/comment-page-1#comment-1971 imsolidstate Tue, 22 Jun 2010 14:11:58 +0000 http://www.imsolidstate.com/?p=506#comment-1971 The step-up converter is TI's TPS61221. It's incredibly small at 2mm x 2mm, SC-70 6-pin package. I made the PCB on my CNC, but it was really at my machine's limits. It worked well, and seems pretty efficient at the load I was using (the AVR). You may want to select a different part depending on your load to get better efficiency. The curves for efficiency vs. current draw are given in the datasheet. They have a few different parts to match high efficiency with current draw. I used the reference design from TI's datasheet to make the schematic. There's even a recommended layout. http://focus.ti.com/lit/ds/symlink/tps61221.pdf The step-up converter is TI’s TPS61221. It’s incredibly small at 2mm x 2mm, SC-70 6-pin package. I made the PCB on my CNC, but it was really at my machine’s limits.
It worked well, and seems pretty efficient at the load I was using (the AVR). You may want to select a different part depending on your load to get better efficiency. The curves for efficiency vs. current draw are given in the datasheet. They have a few different parts to match high efficiency with current draw.
I used the reference design from TI’s datasheet to make the schematic. There’s even a recommended layout. http://focus.ti.com/lit/ds/symlink/tps61221.pdf

]]> Comment on Moisture Meter for Plants by Muris http://www.imsolidstate.com/archives/506/comment-page-1#comment-1963 Muris Tue, 22 Jun 2010 07:04:32 +0000 http://www.imsolidstate.com/?p=506#comment-1963 Hi, I can't see what step-up regulator you are using in this project. Can you share the schematics with us? I am working on an "automatic blinds" and don't have much room for the batteries there, so this booster IC would be just perfect for me! Regards! Hi,

I can’t see what step-up regulator you are using in this project. Can you share the schematics with us? I am working on an “automatic blinds” and don’t have much room for the batteries there, so this booster IC would be just perfect for me!

Regards!

]]> Comment on Moisture Meter for Plants by Olliho http://www.imsolidstate.com/archives/506/comment-page-1#comment-1821 Olliho Mon, 14 Jun 2010 03:29:25 +0000 http://www.imsolidstate.com/?p=506#comment-1821 Hi there, can you, please, supply the schematic diagram for this very interesting project? thanks Hi there, can you, please, supply the schematic diagram for this very interesting project?
thanks

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