Jayemaitch Posted July 11, 2020 Share Posted July 11, 2020 Hey guys! Building an sdrive max with a dip style arduino and have a question regarding wiring for power and future firmware updates has been flashed and its now running and ready to wire up. I understand that u can put in a spdt switch to facilitate firmware updates so there's no need to reseat the #2 pin on the chip. Also I have seen another switch that can be used to switch between sio power and barrel/USB power, but I have only seen diagrams of that with the other style arduino that needs the sio2uno board. Is there a way to wire that up with the dip style arduino? Or shall I just not wire 5v from sio and use external power? I want to install a switch for future firmware anyways. Just looking to cover all bases... Thanks in advance for all your advice... ? Quote Link to comment Share on other sites More sharing options...
AeroDD Posted July 12, 2020 Share Posted July 12, 2020 I put one together with a DIP style Arduino and included two switches. I followed Mr. Robot’s guide in my build. I haven’t tried a firmware upgrade so I’m not 100% sure I got that right, but at least the power switch between SIO and USB works correctly. I’ll try to get some pictures uploaded later. Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted July 12, 2020 Share Posted July 12, 2020 Personally, I never wire the SIO 5V into the Arduino, that way you can never run into problems. I always power mine via it's USB port. btw. are you including the 7407 chip to ensure you can use other devices with the S-Drive I use the SIO 5V to power the 7407 only Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 12, 2020 Share Posted July 12, 2020 @Mr Robot's wonderful site: https://atari8bit.net/de-re-sdrive-max/ Quote Link to comment Share on other sites More sharing options...
AeroDD Posted July 12, 2020 Share Posted July 12, 2020 Here are a few pictures. Sorry they are a little blurry, and please forgive any poor solderwork (I'm a novice at soldering). Quote Link to comment Share on other sites More sharing options...
BillC Posted July 12, 2020 Share Posted July 12, 2020 3 hours ago, TGB1718 said: btw. are you including the 7407 chip to ensure you can use other devices with the S-Drive The OP said the Arduino he was using had the DIP type ATmega328 micorcontroller, disconnecting one pin of this chip is all that is required in order to share the SIO bus, the 7407 circuit is only required when using the surface mount version. Quote Link to comment Share on other sites More sharing options...
Jayemaitch Posted July 13, 2020 Author Share Posted July 13, 2020 Thank you for the replies guys. I too looked at Mr. Robots guide and it is pretty straight forward. I'm just wondering how the switch to determine power source is wired. The schematic shown for that switch is shown for the sio2uno board. Ty for including pics of ur build AeroDD, could u explain how that is wired since we have the same arduino? Once again, thx in advance for the time. Quote Link to comment Share on other sites More sharing options...
StickJock Posted July 13, 2020 Share Posted July 13, 2020 The power switch is wired to either connect the SIO power or not. It does not switch off external power. You can still hurt yourself if you have it plugged into the Atari with a USB (or barrel power) plugged in and you move the switch to SIO. I suppose you could put a diode on the SIO +5 line so that you don't backfeed the external power into the SIO +5 pin? 1 Quote Link to comment Share on other sites More sharing options...
AeroDD Posted July 13, 2020 Share Posted July 13, 2020 13 hours ago, Jayemaitch said: I'm just wondering how the switch to determine power source is wired ... could u explain how that is wired since we have the same arduino? SIO pin 10 is +5V/Ready and in Mr Robot's diagram is wired to the 5V pin on the underside of the Arduino. I just inserted a switch on that wire, so that the switch opens/closes the circuit. A SPST switch would work, but I had two matching SPDT switches, so I only wired one side of the switch. It's a little hard to see when zoomed in (and behind the wires of the other switch), but the red/orange wires are how I wired the SIO +5V line. Also, StickJock makes a really good point, this doesn't disable the USB/barrel power, so you have to be mindful that you don't supply power through both SIO and external power. Their recommendation of a diode on this line is probably a good idea. Quote Link to comment Share on other sites More sharing options...
Mr Robot Posted July 13, 2020 Share Posted July 13, 2020 Yep can confirm, I just break the pin 10 line Quote Link to comment Share on other sites More sharing options...
Jayemaitch Posted July 13, 2020 Author Share Posted July 13, 2020 4 hours ago, AeroDD said: SIO pin 10 is +5V/Ready and in Mr Robot's diagram is wired to the 5V pin on the underside of the Arduino. I just inserted a switch on that wire, so that the switch opens/closes the circuit. A SPST switch would work, but I had two matching SPDT switches, so I only wired one side of the switch. It's a little hard to see when zoomed in (and behind the wires of the other switch), but the red/orange wires are how I wired the SIO +5V line. Also, StickJock makes a really good point, this doesn't disable the USB/barrel power, so you have to be mindful that you don't supply power through both SIO and external power. Their recommendation of a diode on this line is probably a good idea. Thank you very much for ur reply. This greatly helps me and I'm confident going on with the wiring. I bought a variety of diodes including the 1N5819 for the sio connection. Which diode should I use on this power line? And how would it be oriented? Does it matter before or after the switch? And would it matter which way its facing? I read about the orientation of the sio diode so I have that down. I apologize for all the questions. Very new to electronics and Id hate to make a mistake without touching all the bases. Thanks once again! Quote Link to comment Share on other sites More sharing options...
StickJock Posted July 13, 2020 Share Posted July 13, 2020 39 minutes ago, Jayemaitch said: And would it matter which way its facing? Yes, it very much matters which way the diode is facing. Diodes let current flow in only one direction. You want to install it so that power can flow from the 800 to the SDMax. This will prevent power flowing from the USB/barrel power into the Atari. If you put it in the wrong way, it will 1) not power the SDMax from the Atari, and 2) will not protect the Atari from being backpowered. Quote Link to comment Share on other sites More sharing options...
Jayemaitch Posted July 14, 2020 Author Share Posted July 14, 2020 1 hour ago, StickJock said: Yes, it very much matters which way the diode is facing. Diodes let current flow in only one direction. You want to install it so that power can flow from the 800 to the SDMax. This will prevent power flowing from the USB/barrel power into the Atari. If you put it in the wrong way, it will 1) not power the SDMax from the Atari, and 2) will not protect the Atari from being backpowered. Ty for the response. Does it matter where I place the diode? Before or after the switch? And which type should I use? The same as in the sio connection? Quote Link to comment Share on other sites More sharing options...
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