Using the CPC3703 MOSFET you could eliminate the VDD pin and gain another I/O pin since VIN can run as low as 3.3V.
The point of the 3.3V pin is to provide regulated 3.3V to other chips if necessary or allowing power directly from a battery pack like 3xNiMh without regulation.
I like your discrete solution, and I may produce a version with it. The drain current is rated to only 360ma. The LD1117A33 I'm using is rated to 1A. Still 360ma is not too bad especially if I can squeeze all the regulator components on top.
Here's an SRAM module with up to 256KB of memory. Should be able to get full speed data transfers with this just like with the Flash. I'll probably do a separate SD card module that has a single SPI RAM.
A demo board with a socket and some connectors is next.
I decided to find your 8-bit data SRAM modules after discussing them on my 23K256 thread.
I can't believe I hadn't seen this. I know I've read the first few posts of this thread earlier. Had I known about these modules I might have been pestering you even more than I do now.
Are selling these yet?
What size are these chips? I know I have some SOIC 23K256 chips. So if your board use SOIC chips, I could populate my own, if you are selling the boards.
I must confess, yours is a much more elegant solution than my stack of DIPs.
Do you know why these SRAM chips are limited to 32KBytes?
It seems like a 64KByte chip would be desirable. They wouldn't even need to change the chip's instuctions since the 32K version uses a 16 bit address.
I have wondered about adding another set of chips and by using a second chip select line one could have double the SRAM. Or the C3 method of using pulses to select the SPI device could be used and allow one to have even more memory without using up more pins.
Don't hurry getting these to maket on my account. You sure have a lot of projects going. I hope you stop to smell the roses once in a while (and not just solder fumes).
I decided to find your 8-bit data SRAM modules after discussing them on my 23K256 thread.
I can't believe I hadn't seen this. I know I've read the first few posts of this thread earlier. Had I known about these modules I might have been pestering you even more than I do now.
Are selling these yet?
Hi Duane.
Product is ready for sale now via PayPal. PM me if your are ready to buy a kit.
SpinSocket Platform dev-boards are available for $50 via PayPal.
SpinSocket Propeller modules are $50 each.
SpinSocket SRAM add-on modules (no Propeller) fully assembled are $25 each.
All prices are introductory and subject to change. A PropPlug is required for programming.
There is lots of flexibility in these modules. Deep breath ....
4MB of byte-wide Flash is available for the SpinSocket Propeller modules for $6 a pair.
All SpinSocket Propeller modules have a Propeller, 64KB EEPROM, 6MHz crystal, and 2 SO-8 SPI device footprints (includes separate hold/write-protect for each chip but common chip-select and spi clock).
SpinSocket modules can be operated from a single AA Cell battery (1.3V to 4.25V) or with regulated voltage (4.5V to 9V) depending on the module type. Power options are assembled to your specification.
What size are these chips? I know I have some SOIC 23K256 chips. So if your board use SOIC chips, I could populate my own, if you are selling the boards.
The chips are 32KB TSSOP8 footprint.
The only SPI SRAM chips readily available that I can find are 32KB or less size. Having 8 32KB chips in parallel gives a nice 256KB memory.
The SpinSocket-SRAM is an add-on board for the SpinSocket Propeller modules. I have 9 of the SRAM boards + the one I'm testing now. Bare boards are $8.00 each.
The advantage to all these memory configurations as you know very well is low pin count. The surprize is that speed for byte-wirde Flash is comparable to SDRAM and SRAM speed is not too bad.
I have wondered about adding another set of chips and by using a second chip select line one could have double the SRAM. Or the C3 method of using pulses to select the SPI device could be used and allow one to have even more memory without using up more pins.
This is possible. My SRAM board would require a cut/jump to allow a different Chip Select.
BTW: as far as software goes, ...
All modules are programmable in SPIN/PASM.
David Betz' XBASIC will be ready for these modules and other Propeller configurations very soon. A version of ZOG may be released later.
I expect to port RossH's Catalina to these before end of summer (assuming memory models do not require more extraordinary effort).
Other programming languages are possible like BigSpin (on hold), and other languages not requiring external memory solutions.
Don't hurry getting these to maket on my account. You sure have a lot of projects going. I hope you stop to smell the roses once in a while (and not just solder fumes).
There is an old bottle of Cabernet in the kitchen. I will enjoy it's bouquet tonight
I haven't had time to put up a proper web store yet, but should have something ready soon. Getting the web store working is a very high priority, but there are some things I need to finish first. Nick has agreed to host sales of these modules on consignment at GadgetGangster, but that is also work in progress.
The SpinSocket-Flash and SpinSocket-RAM boards are on Tubular's open-source Smorgrasboard.
I'm posting a SpinSocket User Guide (word document) and the doc pack here.
The doc pack contains basic assembly drawings, schematics and parts list.
I'll convert the User Guide word doc to a web-page later for all users.
I've dropped the price of the assembled 4MByte SpinSocket-Flash modules to $40
(includes modules and stacking header options - see the word doc).
I'll sell kits without PCBs for $30 each (add $4 for non RoHS rev A1 PCB).
Smorgasboard rev A2 PCBs do not contain lead.
SpinSocket-Flash modules are programmable today via Propeller-GCC.
These modules have up to 20 free user pins when used with fast Flash cached access.
Modules are programed and can be powered with the Parallax PropPlug-USB.
Comments
since VIN can run as low as 3.3V.
Duane
The point of the 3.3V pin is to provide regulated 3.3V to other chips if necessary or allowing power directly from a battery pack like 3xNiMh without regulation.
I like your discrete solution, and I may produce a version with it. The drain current is rated to only 360ma. The LD1117A33 I'm using is rated to 1A. Still 360ma is not too bad especially if I can squeeze all the regulator components on top.
Here's an SRAM module with up to 256KB of memory. Should be able to get full speed data transfers with this just like with the Flash. I'll probably do a separate SD card module that has a single SPI RAM.
A demo board with a socket and some connectors is next.
I decided to find your 8-bit data SRAM modules after discussing them on my 23K256 thread.
I can't believe I hadn't seen this. I know I've read the first few posts of this thread earlier. Had I known about these modules I might have been pestering you even more than I do now.
Are selling these yet?
What size are these chips? I know I have some SOIC 23K256 chips. So if your board use SOIC chips, I could populate my own, if you are selling the boards.
I must confess, yours is a much more elegant solution than my stack of DIPs.
Do you know why these SRAM chips are limited to 32KBytes?
It seems like a 64KByte chip would be desirable. They wouldn't even need to change the chip's instuctions since the 32K version uses a 16 bit address.
I have wondered about adding another set of chips and by using a second chip select line one could have double the SRAM. Or the C3 method of using pulses to select the SPI device could be used and allow one to have even more memory without using up more pins.
Don't hurry getting these to maket on my account. You sure have a lot of projects going. I hope you stop to smell the roses once in a while (and not just solder fumes).
Duane
Hi Duane.
Product is ready for sale now via PayPal. PM me if your are ready to buy a kit.
SpinSocket Platform dev-boards are available for $50 via PayPal.
SpinSocket Propeller modules are $50 each.
SpinSocket SRAM add-on modules (no Propeller) fully assembled are $25 each.
All prices are introductory and subject to change. A PropPlug is required for programming.
There is lots of flexibility in these modules. Deep breath ....
4MB of byte-wide Flash is available for the SpinSocket Propeller modules for $6 a pair.
All SpinSocket Propeller modules have a Propeller, 64KB EEPROM, 6MHz crystal, and 2 SO-8 SPI device footprints (includes separate hold/write-protect for each chip but common chip-select and spi clock).
SpinSocket modules can be operated from a single AA Cell battery (1.3V to 4.25V) or with regulated voltage (4.5V to 9V) depending on the module type. Power options are assembled to your specification.
The chips are 32KB TSSOP8 footprint.
The only SPI SRAM chips readily available that I can find are 32KB or less size. Having 8 32KB chips in parallel gives a nice 256KB memory.
The SpinSocket-SRAM is an add-on board for the SpinSocket Propeller modules. I have 9 of the SRAM boards + the one I'm testing now. Bare boards are $8.00 each.
The advantage to all these memory configurations as you know very well is low pin count. The surprize is that speed for byte-wirde Flash is comparable to SDRAM and SRAM speed is not too bad.
I wish I knew. Maybe it's a demand problem. There are some 128KB parts available from Cypress I think, but they are not 8 pin chips.
This is possible. My SRAM board would require a cut/jump to allow a different Chip Select.
BTW: as far as software goes, ...
All modules are programmable in SPIN/PASM.
David Betz' XBASIC will be ready for these modules and other Propeller configurations very soon. A version of ZOG may be released later.
I expect to port RossH's Catalina to these before end of summer (assuming memory models do not require more extraordinary effort).
Other programming languages are possible like BigSpin (on hold), and other languages not requiring external memory solutions.
There is an old bottle of Cabernet in the kitchen. I will enjoy it's bouquet tonight
I haven't had time to put up a proper web store yet, but should have something ready soon. Getting the web store working is a very high priority, but there are some things I need to finish first. Nick has agreed to host sales of these modules on consignment at GadgetGangster, but that is also work in progress.
The SpinSocket-Flash and SpinSocket-RAM boards are on Tubular's open-source Smorgrasboard.
I'm posting a SpinSocket User Guide (word document) and the doc pack here.
The doc pack contains basic assembly drawings, schematics and parts list.
I'll convert the User Guide word doc to a web-page later for all users.
I've dropped the price of the assembled 4MByte SpinSocket-Flash modules to $40
(includes modules and stacking header options - see the word doc).
I'll sell kits without PCBs for $30 each (add $4 for non RoHS rev A1 PCB).
Smorgasboard rev A2 PCBs do not contain lead.
SpinSocket-Flash modules are programmable today via Propeller-GCC.
These modules have up to 20 free user pins when used with fast Flash cached access.
Modules are programed and can be powered with the Parallax PropPlug-USB.
Hi David. $25 each fully assembled. $20 each for a parts kit with no PCB.