I've read that John Wilkins was Newton's room-mate and they lived together for 20 years. Is there anything about Newton written by Wilkins?
By the way, there is nothing easily found on google.
Part of the problem may be that Newton's roommate's name is spelled as Wickins or Wickens, not to be confused with bishop John Wilkins, Newton's older contemporary. Since they did live in the same room for 20 years Wickens's testimony would be precious indeed, but alas, as far as I know, the only things Wickens wrote concerning Newton were not about him but to him, letters. Some of the letters might be in the multi-volume Correspondence of Isaac Newton by Cambridge University Press, but not it seems in the online Newton’s Correspondence. It would not help with the most common speculation concerning Wickens, however. According to Waltz's history of autism:
"Others — e.g. Gribbin, p. 178 [Science: A History 1543-2001, BCA, 2002] have suggested a homosexual relationship with his long-time roommate John Wickens, but there is no hint of this in their surviving correspondence."
Spargo and Pounds in Newton's 'Derangement of the Intellect' quote a remark about Newton by Wickens's son Nicholas, but even that is just a reply to an inquiry forwarded to him by his father rather than some kind of memoir:
"He was turning Grey, I think, at Thirty, and when my Father observed y$^{\textrm{t}}$ to him as y$^{\textrm{e}}$ Effect of his deep attention of Mind, He would jest w$^{\textrm{th}}$ y$^{\textrm{e}}$ Experimy$^{\textrm{ts}}$ he made so often wth QuickSilver, as if from thence he took so soon that Colour."
The source is a manuscript labeled King's College Library, Cambridge, Keynes MS I37, not something that would be online either.
According to Nova:
A more recent blow was the departure from Cambridge of John Wickens, Newtons room-mate for twenty years. Wickens became the minister of the parish church at Stoke Edith, married and fathered a son called Nicholas. Though they had through much together, the two friends would never meet again, and exchanged no more than a letter or two in the coming years.
Thus there is not likely to be much. Though see this for some anecdotal details.