For those who don’t know about the stipulations of Pokewalkers, their functions and limitations….
You have to link the Pokewalker to an authentic HeartGold or authentic SoulSilver cartridge in order to use it. You would then select a Pokemon from your PC box, for example Psyduck, to take on a stroll on a selected route on the Pokewalker. You can battle and catch up to 3 Pokemon on the Pokewalker via a mini-game of sorts and after you catch them on the Pokewalker you then would connect to the same linked HeartGold or SoulSilver cartridge same applies to any items to find on the Pokewalker too.
Additionally the main Pokemon (for example Psyduck) you transferred from your PC Box onto your Pokewalker you can use to help you battle and catch Pokemon on your Pokewalker, that’s one of the mini-games on the Pokewalker another mini game on the Pokewalker is to hunt for items.
All Pokemon encountered and caught on the Pokewalker are shiny-locked meaning you cannot get shinies using the Pokewalker. You CAN put a previously obtained shiny pokemon onto your Pokewalker from your PC box but due to there being no color display, think of it as a slightly more advanced DMG GameBoy screen but of course in a smaller aspect ratio.
Also Pokewalkers are not region-locked so if you wanted to you could buy a Pokewalker from a Japanese listing online, reset it and connect it to any language/region cartridge of HeartGold or SoulSilver so long as said HG/SS cartridge is authentic, if said HG/SS cartridge is not authentic then the Pokewalker will be not able to connect to it and therefore cannot be linked to it.
Pokewalkers cannot trade/transfer Pokemon to another authentic cartridge and items on the Pokewalker cannot be transferred to another cartridge either. Only the linked HG/SS cartridge can connect and receive the caught pokemon and found items from the Pokewalker.
Pokewalkers can connect albeit temporarily to another Pokewalker given both Pokewalkers have their own Pokemon onto it like for instance I have two Pokewalkers; one has Crackers the Psyduck on it (linked to HeartGold) and Meatball the Geodude (linked to SoulSilver) and every few hours at a time I can temporarily connect the two Pokewalkers to each other to have Crackers and Meatball have a play date and both Crackers and Meatball will be gifted an item for you to transfer to the respectively linked HG/SS cartridge.
Pokewalkers can ONLY be connected/linked to authentic cartridges of HeartGold or SoulSilver. They CANNOT connect/link to Diamond, Pearl, Platinum, or any other Pokemon game.
Pokewalkers cannot be used to evolve any Pokemon, and yes that does also mean that you cannot use it to evolve trade-method evolution Pokémon such as Gravler into Golem.
BONUS FACT:
A Wii U Fit Meter shell and LCD screen can be used as a replacement shell/screen for a Pokewalker as
Wii U Fit Meter and Pokewalkers are essentially the same thing the only difference is the ROM on the respective board on the inside behind the screen and battery slot. Both Wii U Fit Meters and Pokewalkers use the exact same CR2032 watch style battery and even the same battery covers. So if you happen to want a Pokewalker with a belt clip battery cover you can easily get a Wii U Fit meter that has the same belt clip battery cover from eBay for about $5-$10 and put it on your Pokewalker for very cheap!
^ Important: I would be VERY careful when doing transplant surgery on your Pokewalker if you’re gonna swap the battery enclosure from a Wii U Fit Meter with the broken battery enclosure on your Pokewalker. I’m not sure if there’s any special wiring behind it or not that would connect to the display and/or to the board so I would take things slow throughout the whole process. I do know the display (for both Wii U Fit Meters and Pokewalkers) itself is connected to the board via a thin yellow ribbon connector of which is rather fragile, it’s similar to the yellow ribbon connectors that are spiraled in the hinges of every DS, DS Lite, DSi, 3DS, and “NEW” 2DSXL.
^^ Additionally of course you’ll need a Tri-Wing Y0 screwdriver for their screws and a PH0 screwdriver is also needed for some parts.
For a complete list of requirements, criteria and more info for routes, Pokemon encounters on specific routes, items that can found and more in general check out this Serebii article here:
https://www.serebii.net/heartgoldsoulsilver/pokewalker-area.shtml](https://www.serebii.net/heartgoldsoulsilver/pokewalker-area.shtml)