MichaelMeissner
Senior Member+
According to the SPI guide:
Two hardware related issues are:
I'm wondering if there is a single chip that combines both. I would imagine you would connect CS and MOSI inputs on one side and get CS and MOSI outputs on the other (presumably with VCC and ground thrown in).
Something like:
Preferably in through hole or SOIC-8 (SOIC-6 if it exists). The primary motivation is to save real estate on my prototype boards, but not have to go to custom PCBs, or PCBs smaller than I can solder.
Two hardware related issues are:
- Add pull-up resistors for the CS pin (and D/C pin if used);
- Make the MOSI pin for the device tri-state.
I'm wondering if there is a single chip that combines both. I would imagine you would connect CS and MOSI inputs on one side and get CS and MOSI outputs on the other (presumably with VCC and ground thrown in).
Something like:
Code:
Originally the connection would look like:
Teensy Device
------ -----
3.3v -----------> Vdd
Ground ---------> Ground
MOSI -----------> MOSI
SCK ------------> SCK
CS -------------> CS
MISO -----------> MISO
With pull-up resistors this would become:
Teensy Device
------ -----
3.3v ---------------------------> Vdd
Ground -------------------------> Ground
MOSI ---------------------------> MOSI
SCK ----------------------------> SCK
CS ---+-------------------------> CS
|
+---- 2.2k resistor ---> Vdd
MISO ---------------------------> MISO
If we have to add a a tri-state buffer this would logically be something like:
Teensy Device
------ ------
3.3v ------------------------------------> Vdd
Ground ----------------------------------> Ground
MOSI ------------------------------------> MOSI
SCK -------------------------------------> SCK
CS ---+----------------------------------> CS
|
+---- 2.2k resistor ---> Vdd
|
+--- OE --> +----------+
| |
MISO ----> A ---> + tristate +--- Y -----> MISO
| |
Ground --> + +
| |
Vdd -----> +----------+
So I'm wondering if there is a combined chip:
Teensy Device
------ ------
3.3v ----------------------------------------> Vdd
Ground --------------------------------------> Ground
MOSI ----------------------------------------> MOSI
SCK -----------------------------------------> SCK
+-------------------+
| |
3.3v ---> Vdd -+--> +----------+
| | |
+----+ 2.2k ----+ <-+
| | |
CS -----> OE --+--> + -------- +-------------> CS
| |
MISO ---> A ------> + tristate +--> Y -------> MISO
| |
Ground -----------> +----------+
Preferably in through hole or SOIC-8 (SOIC-6 if it exists). The primary motivation is to save real estate on my prototype boards, but not have to go to custom PCBs, or PCBs smaller than I can solder.
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