Teensy is PJRC. Crossroads is a different place. That 1284 has 16K RAM.
You can likely get a prototype in a short time through the Gigs and Collaborations section of the board.
Crossroads Bob may be up for it or Dr. Azzy or another member here who is also a pro EE.
GoForSmoke:
Teensy is PJRC. Crossroads is a different place. That 1284 has 16K RAM.You can likely get a prototype in a short time through the Gigs and Collaborations section of the board.
Crossroads Bob may be up for it or Dr. Azzy or another member here who is also a pro EE.
well, my application requires bluetooth, as well as sd card reader.
If both can be on-board, and also with a AVR mcu capable of 8KB RAM, that would be perfect.
I have emailed robert my requirements. hopefully everything is well.
p.s. the site is legit right? 
Do you really need a custom-made board? Sounds like a waste of time and resources, to be honest.
Get a piece of perfboard, some female headers, and some wires. If you buy Bluetooth & SD card modules that have the level shifters built-in, you only need to solder some connections, and maybe a 3.3V LDO.
Pieter
PieterP:
Do you really need a custom-made board? Sounds like a waste of time and resources, to be honest.
Get a piece of perfboard, some female headers, and some wires. If you buy Bluetooth & SD card modules that have the level shifters built-in, you only need to solder some connections, and maybe a 3.3V LDO.Pieter
if the price isnt too high, it might be cost-savy for me. international shipping isnt cheap. US15 for shipping teensy. another US15 for shipping a ble breakout. US30 for shipping alone. the teensy and breakout is easily US40.
if the price diff isnt too much, the custom can be a viable option? o_O
I get my Teensies for €23 from a local online seller. If you don't have a local option, international shipping can get pretty expensive indeed ...
Take a look at Bluetooth & SD card modules on Ebay etc. They are dirt cheap (probably < $6 in total), and have free shipping.
Pieter
PieterP:
I get my Teensies for €23 from a local online seller. If you don't have a local option, international shipping can get pretty expensive indeed ...
Take a look at Bluetooth & SD card modules on Ebay etc. They are dirt cheap (probably < $6 in total), and have free shipping.Pieter
my dilemma. i do not have the privilege of time. the ebay china knockoffs arent reliable, as compared to the official ones. if an ebay one comes and fails, thats it. 1 month gone.
I've ordered dozens of components from Ebay, Arduino clones, ESP8266 modules and dev boards, FTDI boards, ATmega and ATtiny chips, ISP programmers ... all of them arrived, and not a single one has failed (yet).
If you're in doubt, just order two.
Is ordering from the US really the only option? Are there no local (re)sellers where you live, that can deliver without astronomical shipping fees?
Pieter
PieterP:
I've ordered dozens of components from Ebay, Arduino clones, ESP8266 modules and dev boards, FTDI boards, ATmega and ATtiny chips, ISP programmers ... all of them arrived, and not a single one has failed (yet).
If you're in doubt, just order two.Is ordering from the US really the only option? Are there no local (re)sellers where you live, that can deliver without astronomical shipping fees?
Pieter
im from singapore. ive called up many local shops for my bluno. many of them sells them at a price similar, sometimes higher, than shipping from the US.
its crazy lol. some even sells higher than directly shipping from US, and expects us to go to their shop to collect it.
i ended up just ordering from US since its sent to my doorstep lol.
of course, will try local sources first, and i reckon bluetooth modules are kinda common.
paying double the item cost for shipping is kinda ridiculous lol.
do all bluetooth modules work the same?
my current bluno is a CC2540 BLE onboard. When i connect to it from the android app, serial messages gets sent through the bluetooth to the phone. as in, once connected, that connection channel becomes the serial communication right?
PieterP:
Do you really need a custom-made board? Sounds like a waste of time and resources, to be honest.
Get a piece of perfboard, some female headers, and some wires. If you buy Bluetooth & SD card modules that have the level shifters built-in, you only need to solder some connections, and maybe a 3.3V LDO.Pieter
I got the impression that the OP is not up for soldering but I'd like to be mistaken.
I don't think that PJRC does custom prototypes but there are freelance engineers who will and they'll get it right quicker.
For all I know, Pieter, you may be one of those!
SD may require voltage leveling on MOSI, SCLK (and CS if used) but not MISO. The card may need a good bit of 3.3V in bursts. There are 6 connections for SD.
74HC4050 hex buffers make nice level shifters, 6 channels per chip.
I have been warned about the cheap ( < $2) SD adapters that 'level shift' with just a resistor. They're hard on the cards, you're better off DIY.
If your project ran on 3.3V you could wire the SPI pins directly to a microSD-SD adapter sleeve to plug micro-SD cards in until you get a proper SD slot.
BT adapters are cheap and need RX, TX, PWR, GND, details up to the adapter.
Just wiring up all the led strips is a lot of work, no?
I've seen a project sink over wiring-procrastination turned into too many issues to fix in time.
If there was room, splitting up the project between 2 MCU's with the Nano doing the BT might be an option.
GoForSmoke:
I got the impression that the OP is not up for soldering but I'd like to be mistaken.
I don't think that PJRC does custom prototypes but there are freelance engineers who will and they'll get it right quicker.
For all I know, Pieter, you may be one of those!SD may require voltage leveling on MOSI, SCLK (and CS if used) but not MISO. The card may need a good bit of 3.3V in bursts. There are 6 connections for SD.
74HC4050 hex buffers make nice level shifters, 6 channels per chip.
I have been warned about the cheap ( < $2) SD adapters that 'level shift' with just a resistor. They're hard on the cards, you're better off DIY.
If your project ran on 3.3V you could wire the SPI pins directly to a microSD-SD adapter sleeve to plug micro-SD cards in until you get a proper SD slot.
BT adapters are cheap and need RX, TX, PWR, GND, details up to the adapter.
what gave you that impression? i have my own soldering iron setup, the iron, stand, clamps, prototype boards, etc. of course im up for soldering.
im using an adafruit sd breakout board. its size is slightly larger than the $2 sd breakout i got on ebay, ebay one arrive later so i havent tried it since i got adafruit's one working first.
since there are no conflicting pins for bt and sd, guess getting breakouts for them are fine.
GoForSmoke:
Just wiring up all the led strips is a lot of work, no?
I've seen a project sink over wiring-procrastination turned into too many issues to fix in time.If there was room, splitting up the project between 2 MCU's with the Nano doing the BT might be an option.
there are only like 4 wires for the led strip..
vin pair to 5v buck converter.. digital pin n gnd to the board..
im not sure spliting to 2 mcus would be a good option, considering the debugging process..
will try teensy and mega for now..
tzijie:
well, my application requires bluetooth, as well as sd card reader.If both can be on-board, and also with a AVR mcu capable of 8KB RAM, that would be perfect.
I have emailed robert my requirements. hopefully everything is well.
p.s. the site is legit right?
Yes he better be! He is a longtime member here and has sold boards to other members.
His reputation is worth more than a few boards.
If you solder, you can DIY a prototype. It won't be on a printed board but can be solid and working.
What you are wanting is maybe less than 30 connections. You will need an iron and a multi-meter.
tzijie:
what gave you that impression? i have my own soldering iron setup, the iron, stand, clamps, prototype boards, etc. of course im up for soldering.
im using an adafruit sd breakout board. its size is slightly larger than the $2 sd breakout i got on ebay, ebay one arrive later so i havent tried it since i got adafruit's one working first.
since there are no conflicting pins for bt and sd, guess getting breakouts for them are fine.there are only like 4 wires for the led strip..
vin pair to 5v buck converter.. digital pin n gnd to the board..
im not sure spliting to 2 mcus would be a good option, considering the debugging process..will try teensy and mega for now..
Huzzah! You should DIY a prototype on perfboard or protoboard, it would be quicker!
If the SD adapter only uses single resistors for leveling you can level the 5V to 3.3V yourself, see if they're not supposed to work on 3.3V inputs as well as 5V. That would make it safer for the SD card in the long run.
Only thing I can think might not work for you is the size of a DIY prototype. Modules on wires might fit in close spots?