Re: RAMPS for Due!
I was going to test things regarding the output states when nothing is connected, as I suspected that stuff may be on by default, but hadn't gotten to that yet. That said, the pull-ups/pull-downs are...
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QuoteCefiar That said, the pull-ups/pull-downs are supposed to kick in when the tristate buffers are "disconnected" in Z mode, so I'm guessing that the tristate buffers are actually somehow loading...
View ArticleRe: RAMPS for Due!
Actually the pull-up in most cases goes to the +VGATE line, which will definitely drive the FETs. I think we may need to bite the bullet and either switch to P-channel FET's in place of the...
View ArticleRe: RAMPS for Due!
About the broken connections, I don't really care, just good that we know it's a manufacturing defect and not something with the design. On another matter, I've been having problems with the ADC ever...
View ArticleRe: RAMPS for Due!
QuoteCefiar Actually the pull-up in most cases goes to the +VGATE line, which will definitely drive the FETs. I think we may need to bite the bullet and either switch to P-channel FET's in place of...
View ArticleRe: RAMPS for Due!
Quotebobc QuoteCefiar Actually the pull-up in most cases goes to the +VGATE line, which will definitely drive the FETs. I think we may need to bite the bullet and either switch to P-channel FET's in...
View ArticleRe: RAMPS for Due!
ambrop7: The 10u caps were originally on the Mega (5V), so we may need to change their values for decent readings on the Due (3.3V). That said, it should be noted that RAMBo has removed those 10u caps...
View ArticleRe: RAMPS for Due!
If you want to hit the FET's harder with direct drive use a 74ACT part to drive them. You will get 24 ma drive with a "normal" part and >=48 ma with a "buffer" part (one example is the 74ACT125 at...
View ArticleRe: building my own 3d printer
This area is dedicated to issues regarding the printer electronics. You might get a better response in one of the more general areas. 1) Why not build a kit? They are as cheap as sourcing parts and...
View ArticleRe: Opensource PIC/ AVR bipolar stepper driver
Does TI work? If you have part sourcing issues, this could get pretty strange. A pre-built controller from China for $40 or so might be your best bet.
View ArticleRe: Sanguish development
I'm on a bit of a break lately but I'm still puttering along slowly. The latest puzzle is the interference from the MCP 2200. I can run a board with external USB to serial converters only if I don't...
View ArticleRe: RAMPS for Due!
Problem with the 74HCT and 74ACT parts is that they're 5V logic only from what I have read (they're +5V with +/-0.5V supply), and 3.3V won't register as a logic "High". If someone can point me to...
View ArticleAzteeg X3 external stepper drives
I purchased one of these boards with no drives for a large robot printer I am building 1 meter of Z travel and an 800mm dia build zone. I am almost done with the wiring but have a problem with hooking...
View ArticleRe: RAMPS for Due!
Regarding the outpus being on when VCC has no voltage: This is due to the way the pull-up resistors are hooked up and the fact we're using N channel FETs to drive more N-channel FETs. Basically with...
View ArticleRe: RADDS RepRap Arduino-Due Driver Shield (32bit)
[attachment 23074 RADDS-16-12-2013a.jpg] first RADDS-Shield arived Have fun Angelo
View ArticleRe: RAMPS for Due!
As far as I know the 74ACT parts are undefined for logic levels when you run them off of 3.3V. That's not to say I haven't run them off 3.3. They don't seem to catch fire and explode... I would only...
View ArticleRe: RAMPS for Due!
QuoteCefiar Problem with the 74HCT and 74ACT parts is that they're 5V logic only from what I have read (they're +5V with +/-0.5V supply), and 3.3V won't register as a logic "High". If someone can...
View ArticleRe: RAMPS for Due!
QuoteCefiar Regarding the outpus being on when VCC has no voltage: This is due to the way the pull-up resistors are hooked up and the fact we're using N channel FETs to drive more N-channel FETs....
View ArticleRe: RAMPS for Due!
Driving the IRLB8743's directly out of the buffers is fine as long as the buffers put out 5V. This also removes the inverted heater lines (no need for FETs to invert them, and their associated...
View ArticleRe: RAMPS for Due!
QuoteCefiar The only issue I see is that with all the specs I've seen on all HC/AC/HCT/ACT, logic "High" is considered anything from 0.5x (typical) to 0.7x VCC (the guaranteed limit at the temp specs...
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