circuit consideration

johnlong

Senior Member
Hi All
when connecting Tbaud rate equipment to the picaxe
what on the hardwear side of things needs to be inplace for
correct operation
I ask this question as Westaust mentioned on a
post lately some arangement for correct operation but I can not remember
which post
if its not too much trouble a line drawing would be nice
regards john
 

westaust55

Moderator
If the equipment being connected to the PICAXE has serial signals at TTL levels matching the PICAXE operating voltage (E.g. 0 to 5 V ) then no other hardware is essential.
SERIN and SEROUT can handing both normal and inverted serial comms.
With HSEROuT you may need an external inverter chip as not all PICAXE parts can handle inverted signals directly.

If the serial comms is from hardware that uses an RS232 protocol for voltage levels (such as PC using the 25 or 9-pin comm connector) then a chip such as the MAX232 to handle the voltage levels will be required.

If you can be more specific about the hardware to be connected and which BASIC commands you are intending to use then folks can provide a more specific answer.
 

lbenson

Senior Member
Note that "T" coms may, depending on the picaxe and the pin used, cause the picaxe to be "phantom powered" on the (picaxe) RX line. This means that power-cycling the picaxe won't restart your program. I found this to be the case on at least the 28X2. The solution for me was a 10K inline resistor to picaxe RX.
 

johnlong

Senior Member
Hi
using pins C.7 and C.6 on the 40x2 hserin hserout
with commands hsersetup B9600_8, %001 for background recieve
hserout 0, ("svt.txt=",QT,#vT) to display the variables value
I have it connected and it is working fine (no resistors direct to the nextion)
just wondered if this was the correct way to connect the 2
with it ideling high if there would be potential problems
regards
john
 

westaust55

Moderator
The X2 parts can accept either iNverted or True serial comms by the use of the bits 2 and 3 in the HSERSETUP parameter.

Accordingly with the display having "TTL" level signals, as you have wired, there is no mandatory need for anything more that a wire between the two components.
 
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